Some reactions of polyfluoroalkyl ethers and the preparation of bis(trifluorovinyl) ether

37

Journal of Fluorine Chemistry, 6 (1915) 31 - 51 0 Ekvier Sequoia S.A., Lausanne - Printed in theNetherlands

Received: October28. 1974

SOME

REACTIONS

PREPARATION

M.

OF OF

BIS

BRANDWOOD,

Chemistry

POLYFLUOROALKYL

P.

(TRIFLuOROVINYL)

L.

Department,

Birmingham

B15

COE

and

University

2TT

ETHERS

(Great

J.

of

AND

THE

ETHER

C.

TATLOW

Birmingham,

P. 0.

Box

363,

Britain)

SUMMARY dl

and meso

tetrafluoroethyl or

boron

The

Bis

(1, 2, 2-trifluoroethyl)

1, 1, 2-trifluoroethyl

trichloride

epimerisation

discussed.

yield

of bis

(1,

ethers bis

1, 1, 2, 2

aluminium

is

2, 2-trifluoroethyl)

and from

(trifluorovinyl)

ether

bis

halides

ethers.

stereoisomers

1, 2, 2-trifluoroethyl

chloropolyfluorodiethyl ether,

with

and

halogenopolyfluoroalkyl

Chlorination

fluoroethyl)

ether

of the dl and meso

1, 1, 2, 2-tetrafluoroethyl

ether

ether gives

and

new

(1, 2-dichlorotri-

ether

is

obtained

by

dechlorination.

INTRODUCTION In the

previous

paper

we -described

[l]

diethyl-

and of ethyl

a range

of new polyfluorodialkyl

of these

ethers

reported, forming

alkyl

Lewis

ether, There

[2]. as

is

much

fluoride,

The

ethers, previously

current

with

some

now

ethers,

only

and the

new examples.

of

are

including

interest

of

to give

reactions

chlorine

chlorofluorodialkyl

anaesthetics

to some

cobaltic

and with

vinylic

accessible

by

ethers.

acids

afford

inhalation

an approach

ethers

the derived

eliminations

ethers

provides

with

and from

(trifluorovinyl) difficulty

methyl

the fluorination

olefin

bissome

in polyfluoropresent

work

38 Reactions described

of

by

cyclic

Tiers

a-perfluoroalkyl with the

directly

[3]

who

group

(150L-ZOO’) chlorine

perfluoroethers

to

the

would

no

ethers

were

chloride

in

a

flow

cleavage.

ethers

carried

on

the

The

react

raw

described isomers,

it

with

materials

[l]; it

1003

to

is

seemed

A

not

give

that

perfluoro[6]

aluminium of

without our

to

recently

with

a mixture

that

that

cleaved

h{ore

react

[4]

cis

and

significant

polyfluoroalkyl

halides.

were and

B

known

were

[5], to

likely

aluminium used

isomers

but

shown

linked

shown

and

5H-tetrafluorooxalans

Thus,

would

groups

cleaved

an

by

atoms

was

chl.orides

been at

completely

it

a-perfluoroalkyl

with

were

temperatures

carbon

Subsequently

system

5-dichloro-ZH,

elevated replace

has

chloride

perfluorooxalans

to

similarly

ZH, 5H-hexafluorooxalan

ring

at

(#A, _
di-n-alkyl

trans-2,

react

oxygen.

with

that

aluminium

chloride

atoms

ring

perfluorooxalans polyfluoro-

showed

aluminium

fluorine

with

all

made

refer

to

which

as dl

previously

and

compound

meso

has

stereo-

which

configuration.

RESULTS

AND

DISCUSSION

Treatment aluminium shown by

of

by

g. 1. c.

g. 1. c.,

after

shortest

the

A

starting

were

shown

(1, 2, 2-trifluoroethyl)

at to

100’

for

16

contain

six

major

preliminary

retained

stereoisomer of

bis

chloride

the

material by

mass

spectroscopy a

CHF

(by n. m.

2 group,

the

absence

r.

spectra

ratio

the

leaving a

a large

indicated

and

(I

and

presence ‘;CH HF very

group

The

next

H

of

cross

its

epimerisation two

products

analysis and

bearing ca

as

and

19

a CHF2CHF not

coupling little

B

i. e.

1

II). of

gave

2:3,

elemental

55

oxygen

with

products

Separation

isomer

occurred,

ethers

indicated

of

approximate

B)

of

distillation,

original

had

(isomer

a mixture

components.

the

spectrometry

chloropentafluorodiethyl

ether

gave

fractional

components in

hr

F

to

n.m.

group

r. and

a fluorine Hz).

be

The

coupling,

of

atom

39 which

was

These

data

ethyl A

1,

and

a feature

as

would

were

The

is

final

combination formula

threo

pair

the

are

ether,

sides,

aluminium results

ether

chloride

are

shown

reaction

times

isomer

A or

obtained,

When

gave

the

results (see

time

as

six

are

by g. 1. c.

as

coupling

and the

loss

These

in Fig.

both

as

III

I. A and

ether

oil

of bath.

It is

that

of whether

within

composition

the limits was

in suggesting

The

clear

irrespective

material,

were

an equal

weight

same

on

and other

possible;

in the

case

isomers

an equal

hours,

useful

chloride Mass

always

a mechanism

1, 2, Z-trifluoroethyl at 135O,

only

spectrometry “F

C4H3C1F60.

evidenced

in this

place.

with

product

Thus,

below).

that the a-fluorine

replaced

groups.

section.

starting

same

to have

spectroscopy

shown

experimental

up to about

aluminium

a formula

showed

same

a

analysis

replaced,

taken

with

by

(1-chloro-2,2-difluoroethyl)

been

are

1, 1, 2, E-tetrafluoroethyl

with

indicated

at the

used

,.r

conditions

refluxed

error

shown

(1, 2, 2-trifluoroethyl)

identical

in the

These reaction

of bis

to determine

were

>CHCl

reaction

was

B was

experimental

this

form

near

n. m

and

has

the

stereoisomers

possible

of bis

paper

atom

erythro.

‘H

has

isomers

but was

two

and elemental

-CHF2

in this

of each

each

is

and

the a-fluorine

as

not been

isomers

to compare

under of

of

and meso

described

B samples treated

Again

spectrometry 19F

work,

(III and IV)

and epimerisation

In order

heated

of products

[l]. Z-difluoro

(I and II;

earlier

cleavage. so far

ethers

1-chloro-2,

of an a-fluorine

from

and which

presence

dl

Again,

reactions

for

little

parent

to be

stereoisomers

expected

C4H4C12Fq0;

and IV

weight

be

of mass

confirmed

of

ether

but it has

isomer

of the

Replacement

by very

formed,

which

spectra

components

B respectively).

accompanied

for

the

2, 2-trifluoroethyl

occurred

both

of the

suggested

atom

by the of cross

product

and elemental

and in the

‘H

n. m

>CHF

disappearance oxygen

one

ether

,.r

was

was analysis

spectroscopy had

been

of the geminal

HF

coupling.

group

Thus,

the

40

CHF=CCPOCHFCHF2

KOH

<

CHF 2CHCLO CHF CHF 2

/

(dl zeo ?

(CHF~CHF)~O

>

Y~;20

t

UV

cez i CHF2CCeF (dl

OCHF

threo

and

(dl

and meso)

(III)

and (IV)

CHF2 ce2 uv

erythro)

>

(CCeF2CCPF)20

(dl

and meso)

L

(IX) Zn

D MS0

(xv)

(cF~=cF)~~

w

CHF2CHCeOCF2CHF2

CHF

--)

CHF2CHCP0 CCIF2CCPF

CHF2CHBrOCF2CHF2 1

(VI) CF2=CF

0 CF2CCeF2

<

Zn

CCeF2 CHFO

CCP2 CHF2 0CF2

CHF2

CF2CCeF2

(VII) (XII)

(XI)

CCPF2 CCPF 0CF2CCeF2

(X)

CHF 2CHC e 0 CH3

(XIII)

t

(XIV)

DMSO

(XVI) Br

21

C BrF2CBrF

OCF2CCeF2

(XVII) CHF2

FIG.

CHFOCH3

I.

C% u;

>

CHF2CHF

0 CH2CP

41 product

(V)

was

There

is

a-CF2

group

bromide poor

assigned

no evidence was

gave

the

that

attacked.

the

An

in a similar

way

CHF2CHClO

reaction

exchange

CF2CHF

2’ employed

conditions reaction

CHF2CHBrO

using

CF2CHF2

The

reactions

boron

trichloride.

ether

was

were

completely

Isomer (IV)

replaced

(VI)

There

the

seemed

in rather

configuration

in all

and is

firstly

based

various

fluorine

materials.

rather

isomer

designated

designated

isomer

B have

designated

isomer

A

In a similar tetrafluoroethyl shown

to have

indicated

and the

the

the

higher

with

some

passed

over

resulting

isomer

heated product

B to be

ca

tenuous

shifts and

of the

starting

than those

those

compounds

than those

but lasting ether

of bis

a single

showed

Thus

isomer

product

by mass and

a to the

Thus,

‘H

n. m. r.

oxygen

type

boron

and

at 260°, the A

trichloride

of chloride

(1, 2, 2-trifluoroethyl) fluoride

1, 1, 2, 2-

1-chloro-2,2-difluoroethyl

in this

aluminium mixture

atoms

to be

4 days,

gave

19F

ether.

advantages

2:l.

of

compounds

points

C4H3C13F40

of (VII)

isomers

(III) to

assignment slightly

field

Secondly

analysis.

seems

two

in those

boiling

BClS

formula

2-difluoroethyl

The

of

cases.

1, I-dichloro-2, to have

yield.

of configuration

in the products

to lower

A.

of fluorine

structure

atoms

ratio

The

is however

shifts

came

elemental

absence

the

retention

atoms

isomer

reaction

in good

of the chemical

1, 2, 2-trifluoroethyl

spectrometry confirmed

B aiways

in 2

a-fluorine

(IV)

chloride.

reactions

chemical

compounds

(VII)

more

on a comparison

designated

at 90°,

interestingly,

aluminium

of these

l9 F

involving

ether.

and hydrogen

The

processes

system

(1, 2, Z-trifluoroethyl)

(III) and

but,

starting

with

A of bis

to give

to be

observed

all heterogeneous

a homogenous

trichloride

similarly

with

were

isomer

with boron

B reacted

was

described to compare

When

heated

varied

than

just

of interest

ratio seems

ether

exchange. were

and in each of isomer

the

aluminium

yield.

and it was

the

structure

under

case

A:

to be thermo-

42 dynamically

the more

stable,

confirming

the

aluminium

chloride

experiments. The by

mechanism

Tiers

of

exchanges

[3]

to proceed

by

abstraction

generated

via

of this

the

type has

formation

of halide

been

postulated

of a carbonium

from

the carbon

ion

atom

a to the

oxygen.

i. e. Attack by

on the

release

carbonium

replacement be

the

oxygen

lone

replacement: with

bis

trichloride reaction place left

a very

leads

from to some

to test

from the

arrangement

unfavourable

situation. has

from

or

-CHF-CHF2. that HF

of HCl It was

loss

from

elimination to yield 19 F and ‘H n.m. r. group fluorine

with

a large

atom

ease

three

geminal

ion

takes

the fluoride

has

provided

HF

from

from

modes or

the

loss

of

an

with

exclusive

elimination:

of HF

from

either

isomer

mode

of

of CHF=CClO-CHFCHF2 the

an

with base,

possible

was

a mixture

and confirmed

boron

that the

dehydrochlorination

experimentally

CHF2CHC1-

indicated

with

of dehydrofluorination

CHF2CHCl

found

which

that

confirmed

carbonium

reactions

On treatment

CHF2CHC10CHFCHF2

indeed

reaction

suggesting

from

above

against

loss

suggest

presence

coupling

the presence

isomers.

of a geminal and no other

as

The

a result

The

as well

of configuration.

the

relative

a favourable

of HF

ether

ion and

this

ethers,

reaction,

side

retention

chloroethers

opportunity

same

centre

support

enantiomeric

isomerisation,

carbonium

positive

isomerisation

and the developing

3 the

or halogen

strongly

experiments,

BCl

between

leading

not use

to less

the

to observe

important

fluoride

rapidly

The

did

results

able

to isomerisation

intermediate

(1, 2, 2-trifluoroethyl)

is

aluminium

are

lead

complex

between

Our

we

Tiers

isomerisation the

pairs.

-

could

The

of X-.

by interaction

since

mechanism,

AlX3F

the aluminium

by release

stabilised

R&OR

ion by A1X3F-

from

of F-

can

results

AlX3 _>

RCF2OR

>CHF

olefinic

of a -CHFCHF2

group,

by

43 Mass

spectrometry

one

chlorine

however each

it

suggests

on

).CCl-0

stable

atom

so far

of

not been The

that

the

between

the

the

two

next

is

and the

elimination

in vinylic

the

be so

due

is

interesting;

accommodated

be

may that

best be

more

a minimum

to the .interaction

n electrons

other

of

stereochemistry

formed

It could

desirable

on F

of

the

can

presence

It has

manner

ether

alternatives.

demonstrated

studied

in this

carbanion

the

values.

to determine

chlorovinyl

p electrons

fluorines

ratio

of HF

fluorines

and any mode

Having

loss

indicating

data,

isotope

possible

possible

of vinylic

puts

these

a developing

and that

number

we

by using

isomer.

than

bond,

supported

than

of the double

the one

observed

positions.

the

replacement

substitution

of

of fluorine

chlorine

for

by chlorine,

hydrogen

in our

fluoroethers. The number

chlorination

of polyfluoroethers

of workers

[7-lo],

by irradation

of the

the

ether

refluxing

Both

of these

more

succeeded

and

whilst

which

with

ethers,

for

more

is

in a sealed is

latter

studied

being

chlorine

is better

the

been

usually

and chlorine

through

controllable

compounds,

the reaction

ether

methods

has

our

out

or

of

passed. the former

lightly

suited

carried

system

being

obtaining

by a

is

chlorinated

to exhaustive

chlorination. Treatment with UV

of bis

an equimolar irradiation component

shown

by n. m. r. in the

analysis hydrogen showed 2:l:l.

available

spectroscopy ca

45:55.

the

had been

gross

(VIII) is

with

,,;CHF

a mixture

a large

F

case

of the

a was

groups

ether, gave

i.e.

one

spectroscopy

diastereoisomers

of chlorine

was

and elemental

n. m. r.

and)CClF

and with

but which

to be C4H3ClF60, ‘H

B)

of diastereoisomers

spectrometry

and

A or

tube

which

packings,

1, 2, 2-trifluoroethyl excess

(isomer

in a sealed

a mixture

structure 19

of-CHF

2, 2-trifluoroethyl

g. 1. c.

Mass

ether

in each

to be

replaced.

the presence

reaction

of chlorine

a compound

on all

confirmed

Thus,

chloro-1, this

ratio

2-trifluoroethyl)

proportion

afforded

single

(VIII)

(1,2,

in the ratio of

l-

Repeat

an inseparable

44 mixture

of the

dl

trifluoroethyl) deduced

ether

in good

of protons

-CC1F2

and

group

with

three

products

by mass

came

way,

ether

“F

and

a%ClF

structure

In a similar

analysis

The two

second

hydrogen

indicates

further

third

this

split

into

The

on the

Thus,

(XI)

coupling

Thus,

assigned

and

3.0

atom

structure ether

the

doublet

Hz.

a to the the

similarly

clearly

oxygen

in the

ether.

to be an isomer 1 by H n. m. r.

shown

a to a;.CF2 8 Hz

54/Hz

structure

shown

again

JHF

This

2, 2-trifluoroethyl

group

1 H

contained

showed

a large

HF

JHF-52.

group

of triplets

1, 2-dichlorotrifluoroethyl

reaction

manner,

2-difluoroethyl

as

atoms

shown

in view JHF

ether

above.

with

excess

1, 1, 2, 2-

chlorine

1, 2, 2-trifluoroethyl methyl (XIV). The

ether The

formation

(XIII)

methyl and

structures of

gave

(XIII)

ether

pure. gave

1, 2, 2-trifluoro of

is

(X)

each

rather

of

of

2. 9 Hz).

ether. of this

chloromethyl

determined

as

was

of the position of the 1 by H and “F n.m.r.

assigned

of the H was

(a triplet

In a similar

ethyl

was

pattern

repeat

1-chloro-2,

is

on a -CHF2

tetrafluoroethyl A

(XII)

J

carbon

to be

(XII) is

gave

2-chloro-1,

position

spectroscopy

solved

of

first

spectrometry

analysis

triplets

below).

C Cl F 0. 4 37 confirmed the

by mass

spectrum

(see

2,2-trifluoroethyl

problem

readily

confirmation

as

F n. m. r.

(XI)

The

The

structure

19

and

indicated

a mixture

chlorine

and elemental

‘H

component

gave

1, 2-dichloro-1,

Z-chlorotetrafluoroethyl

the

again

1, 2, 2-trifluoroethyl

three

was

The

ether.

Further

to contain

C4HC12F20.

the H to be

original

*

2, 2-

was

which

dechlorination

by g. 1. c.

atoms

unreacted

was

1:l.

of chlorine

component

chlorine

spectroscopy.

ratio

separated

no protons

as

The

structure

spectroscopy

subsequent

confirmed

structure

(XI)

in the

2-chlorotetrafluoroethyl

(X).

,.r

proportions

readily

showed

nm .

from

spectrometry

n. m. r.

.,which

The

yield.

1, 1, 2, 2-tetrafluoroethyl

3 molar

elemental

only

(1, 2 dichloro-1,

atoms, spectrometry showing four chlorine 1 H nmr spectroscopy which confirmed the analysis,

absence

of the

(IX)

of bis

isomers

by mass

elemental

as

and meso

were

45 surprising

since

process

we had

We

have

formation usually

it involved

displacement

not observed

previously

found

previously

of vinyl involving

ethers

with these

alkali

(IX)

and

with

zinc

at high (X)

by

chlorine,

of

reaction.

type

ethers

by dehydrofluorination

“molten”

chloropolyfluoroethers

[1]

of fluorine on this

that the

was

difficult,

temperatures.

g ave

vinyl

a

The

ethers

quite

readily

by dechlorination. Treatment afforded

of (IX)

a very

volatile

spectrum

showed

19F

r.

nm .

.

splitting JFF

gem

vinyl) the

three

was

ether

patent

JFF

was

treated

data

of this

were

chlorine

given

interesting

divinyl

for

The

bis

tube

mass

(trifluoro-

previously

claimed

CF(CF3)

and are

OCF2

in fair the

structure

to give

simple

ether

constants

Hz.

to confirm

A very

of doublet

coupling

of FOC

in a sealed

ether.

vapour i. r. -1 at 1840cm and the

105

been

80°

The

expected

In order

(1, Z-dichlorotrifluoroethyl) preparation

trans

has

at ca

doublet

with

the pyrolysis

values.

with

JFF

compound

spectral

our

complex atoms

with that

[Z] from

Some with

three

[ll]

yield.

frequency

65 Hz,

This

literature

agreement

cis

in DMSO

in good

fluorine

in agreement

(XV).

CF2COF.

(XV)

showed

vinylic

95 Hz,

spectrum

material

at>C=C
spectrum

for

dust

back

method

is therefore

bis

of

now

available. way,

treatment

1, 2-dichlorotrifluoroethyl

ether

In the

same

fluoroethyl structure

trifluorovinyl was

analysis,

The

cross

oxygen

order

methods.

addition ether

19F

coupling

to yield

The

Z-chlorotetrafluoroethyl

with

zinc

(XVI)

by mass

in good

but was structure

capable was

1, 2-dibromotrifluoroethyl

was of

gave

2-chlorotetraThe

yield.

spectrometry

spectrum

n. m. r.

dust

and elemental complex

analysis

confirmed

because

of

by first

by bromine

2-chlorotetrafluoroethyl

(XVII). The

Table

indicated

ether

of

1.

n. m. r.

data

of the

compounds

prepared

is

shown

in

in

46

0

.

wjw

r.

v-

mm .

.

mw

hh

mc7 -v

h_

mm --

co .

cum . . ow

z

22

u\ . w

rl

Y

N

c-4

hhh

co v-v

cd

In

3

4

3

4

56

23

4

5

4

5

J34 5.6 J35 1.1 J45 2.1

(2)

F( 3)

\OCF~CF~C~

112.4 J24 5.7 J25 1.1

89.4 (3) AB 138 (5)

J45 52.8 J34 2.9 JAB 149

J23 54.1 J12 3.0 JAB 140

(1) 122.8 (3) 135.7

45

5.75 (4)

5.93 (2)

J 12 66.5 J13 85.2 J23

3

70.9 (1) 75.6 (2)

140.1 (3)

(5 or 1) 89.4 (4) AB

71.7 (1 01‘ 5) 73.9

5.3

J12 54.9 J45 3.1 J56 52.8 J23 6.9 J13 4.2 J46

= J59 5.2

4.2 J 56 = J57 3.0 J78 = J79 52.8 J58 = J69 = J68

J12 54.6 J13 54.4 J23 290 J24 6.3 J34 6.0 J14

73 (5) 89.4 (4) 115

2

(4 or 1) 77.4 (2) 88.1 (3)

5.74 (5) 5.81 (1) 6.15 (3)

5.13 (7) 5.75 (1) 5.95 (4)

F(2) F(1) \,c=c/

1

CF2C1CFC10CF2CHF2

1

CF2Cl-CHF-0CF2CFC1

12

12

71.1 (1 or 4) 74.5

128 (3) 136.2 (8,9)

CF2C1CFC10CF2CF2C1

789

92.7 (2) 125.0 (4) 136.4 (6)

56

91.6 (5,6) 126.1 (2)

CHF2CHBrOCF2CHF2

123 4

CHF2CHClOCF2CHF2

H

and

lgF

n.m.r.

1 continued

data

2

3

H1

/

2

3

‘C=CC10CIPCHF2 (B)

F4

H1

(3)

119

(1)

19F ppm

)C=CC10CHFCHF2 (A)

Compound

1

TABLE

CCl_,F

125._", (2)

rel

139.2

6.54 (1)

5.46 (2) 5.78 (3)

7.12 (1)

5.4 (2) 5.7 (3)

lH

constant

Hz

J14 75

J14 75

512 y5 J13 65 J23 105

Coupling

49 EXPERIMENTAL

Reactions

of polyfluoroaliphatic

Reaction

of bis

aluminium Bis slowly

(1, 2, 2-trifluoroethyl)

(1, 2, 2-trifluoroethyl) added

freshly heated

mixture

lbhr.

The

liquid

The

the black

volatile

colourless

liquid

major

(66cm

from

to yield (ii)

identified mixture

ether

(Col.

P 30. 60 mesh

1: 9

50-100’

N2

(isomer by

A)

i. r.

g.l.

(I) (1.17g)

48. 2. C4H4ClF50

F,

47. 9%);

b.p.

(v)

purity: (Cal.

A)

as

2-difluoroethyl

bis

(1,2,2-trifluoro-;

(0. 9g),

to yield

both

(2. 94g),

A)

(0.4g)

shown

a

to yield

bis

and

H,

ether

nc

2.1;

Cl,

2.03;

Cl,

to be

a mixture

(I) (0. 2g),

1, 2, 2-trifluoroethyl

2000/

Temperature

94-105

H,

of two

50 HB

B (0. 73g)

24. 9;

24. 2;

(5.8g),

107-118° above

C,

C,

105-107’

b.p.

Ucon

(Col.

B)

and n. m. r.

a mixture

2, 2-trifluoroethyl

(Found:

requires

b.p.

above

(isomer

79. 84O (0. 2g)

x 7mm.

to give

(iv)

column

i. r.

(2. Olg) A:

presence

to be bis

by

and isomer

as

1,

106’

b.p.

(vi)

c.

ether

2-difluoroethyl

A)

7.51/hr) (0.4g)

[l]

9. lm

spectrum; by

F,

1-chloro-2,

A)

g. l.c.

separated

by g. 1. c.

(isomer

the

fractionally

bond

shown

from

and

a clear

showed

(i) b. p.

(2.84g)

by

(1, 2, 2-trifluoroethyl)

>95%

spinning

became

water

to give

was

for

in vacua

with

g. 1, c.

fractions:

84-86O

separated

1-chloro-2,

oxide

chloride

solid

distilled

and the mixture teflon

(50. Og) was

at IOO-120’

and the

washed

86-94’

ether

B) [l]

aluminium

was

was

b. p.

programmed ethyl)

yellow

(iii)

components,

Acids

with

reflux

Analytical

eleven

b.p.

comparison;

chromosorb

under

(35. 4g)

an annular

(1, 2, 2-trifluoroethyl) spectral

ether

(Isomer

phosphoric

components,

unidentified;

Lewis

sublimed

distillate

(33. 3g).

through long)

turned

fraction

The

solid. in vacua

distilled

was layer

redistilled

six

ether

to powdered

The

black.

with

chloride

(5Og).

of

ethers

(isomer 17.7;

17.9;

(I) in separated

and ether

nc

(II)

50

(Isomer

B)

(0.4g)

b.p.

Cl,

17. 8;

F,

47. 5;

Cl,

17. 9;

F,

47. 9%);

(viii)

b.p.

(SE

120-130’

30/celite

(0. 5g)

-bis

b. p.

F,

35. 1;

F,

35. 3%);

(ix)

(I-chloro-2,

b.p.

143-145’

a mixture B)

by g, 1. c.

(Cal.

(Found:

C,

requires

C,

spectrum The

(2. 6g). and was gave

with pot

the

Comparison chloride ethyl

after

with

ether

4,

2,

tube

(5. 4g

hydrogen separated distilled

of

with ether

sealed was

contained

(0. 6g), (0. 2g)

33. 0; 33.0;

and

F, F,

35. 1; 35. 3’$),

by comparison b.p.

135-140’

at least

of (IV),

15 components

experiment

isomer

A

result.

products

from

the

diastereoisomers

0. 03mole)

chloride

component

ether

were

the

and 6 hrs

Reaction

The

same

B)

(xi)

In a similar

of the

aluminium

each

(0. 9g)

(isomer

identified

sample;

33, 0:

reaction

of bis

of aluminium

(1, 2, Z-trifluoro-

ether

The with

residue

Cl,

132-135L (III)

Cl,

A)

33.1;

1. 9;

Cl,

1. 9;

(0. log)

Cl,

to yield

2. 0;

H,

an authentic

not investigated.

essentially

H,

22.4;

1, 1, 2, Z-tetrachloroethane

(IV)

to give

nc (III) (isomer

(x) b.p.

80”)

ether

22.3;

H,

pure;

7. 5P/hr)

1. 9;

5. 9g;

A

>95%

N2 ether

22.4;

III

2-difluoroethyl)

C4H4C12F40

i. r.

C,

130-132’,

2. 03;

by g. 1. c.

x 7mm.

H,

2. 3;

H,

(II) 2.13g

22.6;

requires

b.p.

H,

24.2;

separated

9. lm

C,

24. 6;

C,

2-difluoroethyl)

(Found:

C4H4C12F40

bis

of

118-120

b.p.

(Col.

132-134’

C,

(vii)

(l-chloro-2,

separated

(1.3g),

and

80°

(Found: requires

(l.Zg),

1:5

(11) (0. 4g),

120-12.1’ C4H4ClF50

is

heated

and analysed shown

in Table

aluminium

chloride

(5. Og) and

anhydrous

in a Carius

chloride

tube

and washed

evolved. with

a mixture

under

Samples

reflex

were

The

taken

proportion

2. 1, 2, 2-trifluoroethyl

aluminium

and heated

and then

to -180’ was

at 100°

by g. 1. c.

1, 1, 2, 2-tetrafluoroethyl

cooled

to give

was

(6. Og 0. 45mole).

slowly

chloride

at 135’

for

warmed

17 hr.

to 18”

The

liquid

residue

water

(2 x

10cm3)

dried

(3. 3g)

which

was

(5. Og)

(3. 5g) (MgSC4)

separated

The

when was and

by g. 1. c.

A B

A B

A B

2

4

6

isomer

(CHF~CHF)

A B

2

0

Time h

TABLE

2o

34.2 32.6

39.4 35.6

40 38

100

20.6

22.0

27.2 23.2

27.2

29.4

100

(CHF~CHF)~O B A

Distribution

18.3 20.6

18.0 20.0

14.7 17.4

7.3 8.8

6.8 8.5

CHFzCHCBOCHFCHFZ B

A

Product

'$

11.0 12.0

8.9 9.4

8.7

8.0

(CHF~CHCB)~O A

7.3 5.4

4.5 3.3

2.2

2.7

B

52 (Col.

A 80’)

to give

81-82O

C4H3C1F60

Cl,

16. 8;

F,

52. 1;

requires

C,

22. 2;

H,

1.4;

Cl,

16.4;

F,

52.7%)

of

1, 1,

2, 2-tetrafluoroethyl

aluminium (6g)

and

in a Carius

tube

residue

was

(HF

decolourised

and redistilled

clear

liquid

(2. 8g)

material

5%

for

sodium

separated

2, 2-tetrafluoroethyl

was

ether

phosphoric

0.9;

F,

43.7;

Br,

30.3;

C,

18.4;

H,

1.2;

F,

43.7;

Br,

30.6%).

boron The were

was

(Col.

A

(isomer

ether

(5. Og 0. 03ml)

at 90’

worked 1309 A)

B)

i. r.

and n. m. r. Reaction

with

to give

a

to give

109’

(i)

(Found: requires

(Isomer

trichloride

in a sealed

up as

above

to yield

(1-chloro-2,

and

(0.09g)

A)

with

(ii)

bis

both

Carius

after

identified

0.05mol)

tube.

separation

Z-difluoroethyl) (1-chloro-2,

5..9g

ether

The by (III)

2-difluoroethyl)

by a comparison

g, 1. c.

ether of their

spectrum.

of bis

(1, 2, Z-trifluoroethyl)

ether

(Isomer

B) with

trichloride

In a similar

(1. 29)

and boron

17 hr

(i) bis

(isomer

afforded

b. p.

ether

for

(3. 6g)

(IV)

boron

washed

C4H3BrF60

(1, 2, 2-trifluoroethyl)

which

trichloride

heated

tube

oxide

black

2-difluoroethyl

(0. 5g)

H,

The

layer

g. 1. c.

1-bromo-2,

nc (VI)

was

The

solution,

by preparative

and (ii)

tube

to 18’.

organic

bisulphite

from

heated

collected.

a red

18.1;

of bis

The

slowly

C,

Reaction

(8. Og) were

12 hr.

warmed

to give

in vacua

(1. 4g)

bromide

(0. 5g)

in vacua

with

water

at 60’

and then and HBr)

distilled

1, 2, Z-trifluoroethyl

bromide aluminium

opened

material

l,l,

(1. 15g)

1. 5;

to - 180°

starting

nc (V)

H,

volatile

was

ether

(ii) l-chloro-

22. 5;

ether

together cooled

(0. 5g);

C,

with

The

material

(Found:

Reaction ether

starting

1, 1, 2, 2-tetrafluoroethyl

2, 2-difluoroethyl b. p.

(i)

bis

experiment

(1 -chloro-2,

and its

isomer

to the

above

2-difluoroethyl) B (1. 92g)

(IV),

the

ether

ether

(III)

(5. 6g) isomer

A

53 Reaction ether The above

of

with

1, 1, boron

ether

yield

a clear

nc

and boron tube

30. 9;

Cl,

42. 6;

F,

30. 5%).

of bis

with

aluminium

The

ether

The

product

(i) bis

(3.Og)

isomer

B (0. 8g).

ether The

ether

48 hr.

The

of

i. r.

(>95%

gave

(1:l

(Col. A)

1. 2;

A)

(2P/h)

273g) A

at 260°.

100’)

(1. 5g)

to give

and isomer

spectra,

isomer

2-difluoroethyl

mixture

separated

a clear

liquid

gave

(i)

A

B

In a

(1. 6g)

1, 2, 2-trifluoro-

was

B)

(0.07g)

b. p.

isomers

A

and B gave C4H3C1F40

cooled,

(1. 93g).

Separation

starting

(Found: requires

C, C,

flask

from

water

(lg);

(ii)

(isomer

A)

1, 2, 2(0. lg)

26. 9;

of a mixture

H,

1. 9; 1.7;

and

phosphoric

1-chloro-2-fluorovinyl

H,

for

of a portion

ether

27. 2;

(15g)

at 125’

into

material

Analysis

87-89’.

hydroxide

poured

in vacua

1, 2, 2-trifluoroethyl

(isomer

potassium in a nickel

and distilled

(iii)

86-88’;

A)

together

b. p.

42. 6%).

(isomer

isomer

heated

1-chloro-2-fluorovinyl

F,

H,

(Isomer

beads

and n. m. r.

1-chloro-2,

were

by g.1.c.

42.8;

to

1.4;

of nitrogen

by g. l.c.

B (4. 5g)

trifluoroethyl

F,

H,

lg.?;

ether

on glass

ether

their

reaction

layer

to give

(1.73g)

C,

in a stream

separated

isomer

(2. 50g)

(15cm3)

oxide

above

(I)

in water

lower

up as

redistilled

19. 5;

requires

passed

fluoride

was

Dehydrofluorination

the

was

from

experiment

was

as

2-difluoroethyl

C,

(1, 2, 2-trifluoroethyl)

aluminium

identified

Working

which

(Found:

heated

fluoride

(3. 7g)

similar

ethyl

148’

(1, 2, 2-trifluoroethyl)

(0. 75g)

4 days.

1, 1 -dichloro-2,

C4H3C13F40

F,

(11. Og) were

(IO. 2g)

b.p.

42.4;

heated

liquid

(7. 6g)

Cl,

over

for

2-difluoroethyl

(VII)

Reaction

trichloride

at 120°

colourless

1 -chloro-2,

ether

1, 2, 2-trifluoroether

trichloride

(log)

in a Carius

yielded

2, 2-tetrafluoroethyl

Cl, Cl,

ether of 20.0; 19. 9;

54 Chlorination

(1)

of

With

The in

a

tube then

Carius

and

chlorine

bicarbonate

in

give

(i)

87-89’

two

A

.,r

in

of

the

liquid

two

In refluxing same

but

(2

oxide

gave

a

by

with

(VIII)

Cl,

x

10cm3).

clear

liquid

(0. 4g) F,

to

g. 1. c.

2, 2b. p,

52. 3:

16.4:

product

35’.

sodium

preparative

16.4;

1.1;

at

-180’:, chloride

1-chloro-1, nc

hr

to

washed

F,

be

52.6”;).

a mixture

integration.

We

g. 1. c.

available

packing

experiment

of C,

15.0;

ether as

(5. 4g)

Cl,

by

with

up

were

of

unable to

isomer

F

(10. as

to

n. m.

be

r.

6g)

above a

us.

I3

to

Cl,

44.3;

which in

44. 6;

F,

be

35. 6;

a

a

peak

on

1:l

mixture

ether

nc

(IX)

C4C14F6C

35.7%).

it

was

chlorine six

F,

were afforded

single

(1, 2-dichlorotrifluoroethyl)

14. 9;

but

chlorine

g. 1. c, 19

by

experiment

through above

bis

and working

shown

indicated

subsequent

result

any

7 days

(7, 63g)

(Found: C,

a

by

following

A) for

isomers

126’

requires

the

(isomer above

columns

the

b. p.

and

on

hydrogen

were

chlorine

as

colourless

46:54

14

any

water

Cl,

the

for frozen

and

(ii)

H,

showed

ratio

light

was

ether

22.2;

2lmmol)

been

separated

1. 3;

chlorine

results.

ether

several

was

H,

isomers

this

Excess

The

of

the

same

irradiated

C,

spectroscopy

these

repeat

(2)

w/v)

(0, 56g);

21. 9;

requires

separate

gave

(1. 87g)

UV

allow

phosphoric

material

C,

isomers

to

5%

A)

(1,46g,

residue

1, 2, 2-trifluoroethyl

C4H3C1F6C nm .

to

The

from

to

(Isomer

and

having

20’

(1 5cm3,

aliquot

(Found:

19F

to

ether

chlorine

exposed

evaporate.

starting

trifluoroethyl

and

contents

warm

vacua

An

(3.17g). to

to

solution

Distillation

and its

opened,

to

of

2lmmol)

tube

allowed

ether

proportions

(3. 8g,

was

and

(1, 2, 2-trifluoroethyl)

equimolar

ether

sealed The

bis

hours,

found was

that passing

irradiation yields

of the

a

55 Chlorination

(1)

a

of

With

1, 1, 2, 2-tetrafluoroethyl

3 molar

equivalents

The

ether

Carius

tube

were

hr.

The

product,

63

distilled

in

vacua

Separation ethyl

(2. Og,

by

16. 0;

Cl,

irradiated

from

g. 1. c.

with

A

at

35,

34.

8;

F,

43.

8%);

1;

0.6;

(iii)

ether

43. (ii)

nc

C4HC12F70

(0. lg)

b.p.

83’

35’

(XI)

(2)

With

The large

ether

liquid

(22.

spinning

tube

8g)

afforded nc

water clear

(i)

(X)

(10cm3) liquid

C,

C,

17. 9;

17. 9;

H,

H,

C,

0.4%)

2, 2-

18. 4;

and ether

0. 6;

F,

49.

F,

49.

5%).

0. 4;

(Found:

15. 8;

(Found:

H,

92’

2-chloro-1,

74O

17. 9;

was

(2. 32g).

b. p.

requires

b. p.

for

2-chlorotetrafluoro-

(0. 9g)

2-chlorotetrafluoroethyl (0. 22.g)

lamp

and at

chlorine

18@ for was

column

(14.

7

give

ether

2g)

days.

distilled

to

dichlorotrifluoroethyl

nc

(XII)

6;

were

irradiated

Working

through

a

up

teflon

as

7g)

i‘d entified

a

above

banded

2-chlorotetrafluoroethyl (16.

in

gave

annular

1, 2-

by

comparison

of

its

spectrum.

i. r.

Chlorination

The sealed gave

of

ether Carius

a

colourless

preparative

ether

nc

Cl,

27. 0;

and

(ii)

methyl

(2. 3g) tube

1, 2, 2-trifluoroethyl

and

as

(0. 3g)

chlorine

above

liquid g. 1. c.

(XIII)

in

chlorine

which

band

C, C,

(20g)

Carius

a

sealed

UV

1, 1, 2, 2-tetrafluoroethyl

(Found:

excess

to

31mmol)

pressure

with

C4C13F7@

requires

requires

oxide

3;

1, 2-dichlorotrifluoroethyl

C4HC12F7C

washed

ether

F,

(2. 2g,

a medium

being

ether

chlorine chlorine

phosphoric

col.

Cl,

trifluoroethyl

by

and

1, 2-dichlorotrifluoroethyl

C,

H,

of

10mmol)

after

1, 2, 2-trifluoroethyl

for

4

(1. Ig)

were

hr.

Working

Separation

(2. 35g).

gave

(i)

1 -chloro

b.p.

82’

(Found:

C3H5C1F20

1, 2, 2-trifluoroethyl

requires

ether

C,

up

of

as

C,

in

27. 7; H,

3. 9;

ether

nc

a

before

a portion

2, 2-difluoroethyl

27, 6;

chloromethyl

irradiated

(1. 3g) methyl

H,

4. 0;

Cl,

27. 2%)

(XIV)

(0. 42g)

a

56 b.p.

97’

(Found:

C3H4C1F30

24. 3;

over

addition

distilled

was

2. 7;

24. 2; Cl,

F,

38. 4;

23. 9;

F,

38.4%).

1, 2-dichlorotrifluoroethyl

(2. lg)

complete

was

of product

(8.87g)

232

M Cl

ether

was

irradiation

the

was

114’

26.8; 33. 9;

36-38’.

, 147

to give

the

C,

deduced

Cl,

The

of bis-(1,

of zinc

D. M.S.

(50cm3)

produced to the

which

top of

the

was

dust

added

starting

material

and the

temperature

was

bubbled

through

as

Cl,

Highly in a liquid

condenser. complete

raised

the mixture.

trap.

were

peaks

The UV

bromine

to give

ether

nc

total

requires

at

C2F4.

under

40.4

nc

(XVII)

halogen

C,

as

12.3;

27. 1 deduced

Cl,

ether

9.0%).

(IX1

to a magnetically-stirred

(12, Og) and zinc

collected

reflux

Br,

which

ether

gave 100

chlorine

C4F7Br2C10

at 50-60°.

was

spectrometry

34. 3;

halogen

Stark

products

2-dichlorotrifluoroethyl)

(21. 9g)

suspension

F,

8. 9;

40. 7 total

ether

0.

12. 2;

to 87O

(6.8g)

and a further

combined

and with

When

increased

CF2C135CF2,

ether

added

(16.7g).

product

apparatus

with

(6, Og)

was

trifluorovinyl

treating

starting

was

2-chlorotetrafluoroethyl

(Found:

Dechlorination

The

135

by

isomers)

in a Dean

the

Mass

M-CF2C1,

characterised

Br,

collected

powder

at 75’

The

4 hr.

obtained.

1, 2-dibromotrifluoroethyl b. p.

(mixed

through

zinc

(30cm3)

temperature for

passed

of

2-chlorotetrafluoroethyl

b.p. 35

S. 0.

ether

value

was

to give

(XVI)

the

the mixture

2P/hr

distilled

suspension

in D.M.

mins)

at this

from

Nitrogen

(0. 4g)

(30

and maintained

F,

Cl,

2-chlorotetrafluoroethyl

chloride

dropwise

Cl

H,

a magnetically-stirred

zinc

the

of

C,

2. 8;

H,

X

To and

24. 5;

requires

Dechlorination ether

C,

the

to 75’ The

chloride volatile air

When mixture

the was

in

material

cooled

and nitrogen product

(0. 4g)

was

trap

addition

attached of the

vigorously ZP/hr

which

stirred

was

collected

in the

57 liquid

air

(8. 2g,

trap

66.7%)

M-COF,

was

this

were

under

sealed

irradiated

with

comparison

81

vinyl

UV

to give

CF2CF,

78 CF2C0.

vacuum

of its

the

ether

in a Carius

for

i. r.

dichlorotrifluoroethyl)

(trifluorovinyl)

spectrometry

ether,

light

bis

Mass

17’.

97 CF2CF0,

characterise

by

purified

b. p.

and n.m.

ether

(0.7g) tube

The

5 hr. r,

ether

gave

178

M,

In order

to

(XV) 131

and chlorine

(1. 20g)

and the mixture

product

spectra

(0.6g)

was

to be bis

(1, 2-

(IX).

REFERENCES

M. J.

Brandwood, Fluorine

P.

Chem.,

L.

Coe,

1

(1975)

C.

S.

Ely

and J.

C.

Tatlow,

521.

2

USP

3

G.V.D.

Tiers,

J.

Amer.

Chem.

Sot.,

-77

(1955)

4837.

4

G.V.D.

Tiers,

J.

Amer.

Chem.

Sot.,

-77

(1955)

6703.

5

G. V. D.

Tiers,

J.

Amer.

Chem.

Sot.

, -77 (1955)

6704.

6

J.

7

USP

3, 469, 011

8

USP

3,449,

504

(1969).

9

USP

3,461,

213

(1969).

10

11

3, 326, 984

Burdon

(1967).

and G.

R.

C.

Terrell,

J.

F.

Vitcha,

E.

Chivers,

unpublished.

(1969).

L. J.

Speers,

A.

Med.

Chem. Stamp,

W.

S.

Durrell,

E.

C.

C.

D.

Padgett,

J.

Polymer

J.

Szur,

T.

, -15 (1972) G.

Sci.,

Ucciardi

604.

Westmoreland Pt.

A,

and

2

(1965)

and 4065.

shown