Synthesis of some ethynyltrifluoromethylfurans and their polymerization

Journal of Fluorine Chemistry, 31 ( 1986) 45 l-459

451

Received: January3, 1986;accepted: February10.1986

SYNTHESIS

OF SOME

AND THEIR

POLYMERIZATION

TAKASHI

OKANO,

KENZO HOSOKAWA

Government Kita-ku,

ETHYNYLTRIFLUOROMETHYLFURANS

TERUO

UEDA,

KATSUKIYO

and HIROSHIGE

Industrial Nagoya,

462

ITO, KAZUO

KODAIRA,

MURAMATSU

Research

Institute,

Nagoya,

(Japan)

SUMMARY

Some prepared

trifluoromethyl according

chlorofluorovinylation

tuted

polymerizations

were

2,3-bis(trifluoromethyl)furan insoluble

polymer

were

di-

of the electron-

and the initially Thermal,

y-ray

investigated,

thermally

in a violent

However,

2,3-bis(trifluoromethyl)-

because

groups group.

ethynylfurans

of Okuhara.

so smoothly

trifluoromethyl

dichlorofluorovinyl

oxidation

substituted

of lithiated

furan did not undergo withdrawing

group

to the method

induced,

or

and 1,4-diethynyl-

polymerized

exothermal

substi-

to give

an

reaction.

INTRODUCTION

As a part

of

our continuinginterestinthe

fluorine-containing first

synthesis

methyl

group

ethynyl

dealing

substituted

with

compounds

the hitherto

ethynylfurans

chemistry

[ll, we describe unknown

and their

of

here

the

trifluoropolymeriza-

tions.

RESULTS

AND DISCUSSION

As previously reacts

with

good yields precursors

reported

by Okuhara

[21, lithiated

1,1-dichloro-2,2-difluoroethylene of dichlorofluorovinylfurans, for ethynylfurans

0022-1139/86/$3.50

by treatment

furan

(1) to afford which with

are useful

as

n-butyllithium.

0 Elsevier Sequoia/Printedin The Netherlands

452 in the case of the trifluoromethylfurans,

However, results esting

were that

obtained,

as shown

the product

ratio

in Table

different it is inter-

Thus,

I.

of 2-(2,2-dichloro-l-fluoro-

vinyl)-3,4-bis(trifluoromethyl)furan

(2) to 2,5-bis(2,2-di-

chloro-l-fluorovinyl)-3,4-bis(trifluoromethyl)furan larger

at higher

methyl)furan

reactant

ratio

of 1 to 3,4-bis(trifluoro-

It is obvious

(4).

(2) was

that 1 was

dilithiofuran

5 because

Br2 gave

2-bromo-3,4-bis(trifluoromethyl)furan

only

tion product

quenching

not derived

of monolithio

derivative

by the equimolar

reaction

ether

The lithium

at -30°C.

(eq. II) is considerably

olefin with

by addition

exchange

faster

with

5, bromina-

formed

reaction

directly

of 2 with

of 1 (equimolar

of 3 (Table

+ CF2=CCI2

3-fold

of 1 with J_ excess

to 2) yielded

of 2. changed

only

almost

of z bis-

parallel

I).

(1)

slow

1

7

+2

CF3JLCF3

fast

8

+

Li

0

cF3jTiJcs 0

CF=CCI;

CF3mCF3

l-

.

CC12=CF

0

CF=CC12

(II)

(In)

+ LiF

3 CF3

7

CF3nCF3

Li

0 6

5 2 Therefore,

l

when

low, 2, which

z

the molar

firstly

Br

1

---.g!!

? ratio

formed

of j_to the lithiofuran

in the reaction

in

of z and 2

than the reaction

3 (eq. IV), and the yields the recovery

2 which

furan

of the furan 4 with n-butyllithium

the reaction

In fact,

(eq. I). followed

of the lithiated

from

-7 is (I), changes

453

* N

.. u-l .

ul

m m

. w ..

0

0

m

I-ln

01

cr

Q

m

454 quickly

to deprotonated

8 that reacts

the ratio

of 1 to 1 is large

the ratio

of 1 to 2 is less than

run 1 and 2 in Table tially

the reaction

high,

reaction

(II) even

confirmed

from

phenomenon C-5 position

caused

trifluoromethyl

group

was prepared lithium

from

in ether

between

Treatment gave

(see

than the This

run 3 and 4.

can be

The above

C-Hacidity

of the

of the

and the di-

2-lithio-3-trifluoromethylfuran

3-trifluoromethyl

decrease

furan

product

-12.

of C-H acidity

ethynylfurans

(74%), 14

product

This

from

2, 3 and u 13

(9) which

(IO) with G-butyl-

mono-dichlorofluorovinyl

of the compounds

the desired

method, one

in the C-l position.

gave only

the expected

faster

position,

If

1 is substan-

by the electronegativity

(51 %), and no bis-substitution with

addition

method.

bytheincreasein

at the adjacent

group

On the contrary,

addition

3.

addition

of 1to

(I) is relatively

of 2 affected

chlorofluorovinyl

in the usual

the ratio

in the usual

the comparison

maybe

1 to afford

as in the inverse

When

I).

with

11_

is consistent

2 to -* 11

with g-butyllithium (67%) and s

(48%),

respectively. 1) "BuLi -"BuCl -LiF 2) H20 Rl

2; CF3 2; CF3 c;

H

R2 H

13;

-CF=CC12 H

with

those

merization

R2 H

14; CF3 15;

The thermal gave oligomers

RI CF3

and y-ray

of roughly

H

induced

polymerizations

2000 molecular

of phenylacetylene of 13 increased

-C-CH

H

[31.

along

weight,

of -13 and -15 comparable

The rate of thermal

with

the increase

oligo-

in tempera-

455

ture, as estimated 100°C

27 % at

from

the conversion;

ization of -15 was nearly 23 % at 70°C for 480 h). of 13, conversion ture.

28 % at 70°C for 480 h,

for 105 h, 36 % at 15O'C.

was

On the other

equal

The rate of oligomer-

to that of -13 (conversion of l5; induced oligomerization

In the y-ray

46 % for 1.4 x IO6 rad at room

hand,

the rate of thermal

tempera-

polymerization

of

of -13 and -14 was ten times larger than those of oligomerization 15, where14- becameglassy at 70°C for 53 hand the conversion was

30 %.

The rate of polymerization

fast that occurred

the ampoule at 100°C.

the presence

of -14 above IOO'C was so for instance, such an explosion

exploded;

Such higher

exotherm

would

better

to polymerize

erized

firstly

-14 in two steps. at 70°C and then above

at 15O'C

no polymerization

proceeded

further

maximum

polymerization

at 300°C,

conversion

is conceivable

that the residual

the net of the polymer that there

in the polymer U-The

polymerization

the oxidation

poly(diethynylbenzene)

and

temperature

15O'C)

was

of 14

370°C

This

groups

In the

was

93 %.

It

were

locked

to migrate.

It is

assignable

to -C-CH

polymerization

of the polymer

formed

in

of in the

of -14 was 28O'C in both nitrogen was nearly equaltothose of

which

decomposition

ethynyl

80 %, but

time.

conversion

and unable

temperature

became

for longer

no IR absorptions

from

atmosphereandinair,

polymerization

-14 was polymAfter the poly-

is 80 % atl50'C.

the maximum

chains

were

formed

decomposition

oxidation

by

Acetylene IOO'C.

for 170 h, the conversion

meansthatthe

noticed

caused

in the furan -14 of which give a net polymer. Therefore, it was

polymerization

merization

was probably

ofthetwoethynylgroups

[41.

poly(diethynylpyrrole) of the polymer

formed

(for 53 h at 70°C and then

in nitrogen

and 336°C

The

in the thermal for 170 h at

in air.

EXPERIMENTAL

IR spectra were

recorded

tra were R-20B

were

recorded

on a Shimazu

recorded

at 56.45 MHz,

on a Hitachi

GC-MS

7000.

on a Hitachi R-22 respectively.

285H.

'H- and

Mass "F-

spectra

NMR

spec-

at 90 MHz and on a Hitachi Chemical

shifts

were

re-

456

ported

in parts

per ,million in downfields

internal

standard

dard

"F,

for

1H

for

and from

SiMe4

as an

as an external

stan-

respectively.

3-Trifluoromethylfuran

(JO) and

methyl)furan

(4) were

viously

[51.

E-Butyllithium

methods

reported

conducted

(6) from

CF3COOH

under

prepared

3,4-bis(trifluoroby the methods

and 1 were

All reactions

[2,6). nitrogen

atmosphere,

reported

also prepared

preby the

of E-butyllithium with

were

use of sodium-dried

ether.

2-(2,2-Dichloro-l-fluorovinyl)-3,4-bis(trifluoromethyl)furan

(2) and 2,5-bis(2,2-dichloro-I-fluorovinyl)-3,4-bis(tri-

fluoromethyl)furan

(2)

(a) The usual solution stirred

solution

-30--35'~in the

same

added

addition

(1.6 mol/l,

7 min,andthe

poured

into

separated, drous

washed

(2.1 g, 5.0 %). df"

1.696;

"F

20.04

m/z

rel.

temperature

ice water

Na2S04,

containing

with

After

film)

(CF3 in C-3),

for 2 h.

cm-';

19.26

was

stirred

at

282 mmol)

a vigorous

was

boiling

and the mixture The mixture

and water,

dried

layer with

was

was was anhy-

2 (9.5 g, 30 8) and 3

(50 mmHg);

1008

to a

(100 ml) at

The organic

to obtain

2: bp. 90-l°C

intensity

mixture

HCl.

aq. NaHC03

and distilled

IR (neat

in ether

(50 ml) was added

at room

ethereal

dropwise

Then, j_ (25 ml,

in one portion.

anadditional

kept stirring

was added

resulting

for 1.5 h.

to the mixture

g-Butyllithium

mmol)

(20.1 g, 98 mmol)

of 4

temperature

subsided,

method:

70 ml, 112

ni"

'H NMR

(CF3 in C-4),

1.4165; (CC14)

-20.82

7.97 (-CH=); (-CF=);

MS

(%) 316 (98, M+), 297 (24), 288 (20), 281

(100). Anal.

Calcd

Found:

for

C8HC12F70:

C, 30.15;

C, 30.31; H, 0.32.

H, 0.40.

2: bp. 115-20°C (40 mmHg); ng" 1.4621; die 1.786; IR 1016 cm -1; "F NMR (CC14) 19.54 (CF3), 21.81 (-CF=); MS m/z (%) 434 (11, M+), 393

432

(30), 366

Anal.

Calcd

(49),

for

a mixture

428

(77), 397

(IO), 395

(29),

(18).

C 10C14F80:

(b) The inverse 300 mmol),

430 (IOO),

(17), 364

addition prepared

C, 27.94.

method:

Found

C, 27.84.

To ice-cooled

1 (27 ml,

with 4 (10.0 g, 49 mmol)

and

457

E-butyllithium ether

ethereal

solution

(85 ml) was added kept

dropwise

mixture

was

stirring

yielded

2. (3.6 g, 23 %) and

(57 mmol,

1.6 mol/l,

in 15 min,

and the resulting

at 0°C for 2.5 h. s(3.1

Work-up

37 ml) in

as above

g, 15 %).

2-(2,2-Dichloro-l-fluorovinvl)-3-trifluoromethylfuran

(11) fi-Butyllithium

ethereal

mmol)

was added

ether

(30 ml) at -3O-

kept

stirring

mixture

to a stirred

stirring

at room

(1.6 mol/l,

added.

added

M+),

229

Anal.

lgF 20.00 (lo), 219

Calcd

a vigorous

boiling

for 30 min.

Found;

C,

(CF3), -24.33 (23), 213

for C7H2C12F40;

subsided,

mixture Work-up

was

(-CF=);

as above gave

;-Butyllithium

ethereal

mmol)

was added

dropwise

mmol)

and ether

(100 ml)at

was kept as above

(160 mmHg); 1008

niO

199

(98),

Anal.

C, 33.77;

C,

(CC14)

18.90

for

41.91;

H, 0.81.

(1.6 mol/l, mixture

-45 - -5O'C at the same

acetylene

temperature

3.61 (-CECH),

(CF3 in C-4);

159

47-8'C

(9 mmHg);

232

and the for 30 min.

7.73 (-CH=);

MS m/z

(%) 228

"F

20.14

(85, M+), 209

(85).

C8H2F60

C, 42.13;

H, 0.88.

H, 0.91.

3 (19.2 g, 45 14 was

145 ml,

of 2. (22.3 g, 70

in 20 min

2,5-Bis(ethynyl)-3,4-bis(trifluoromethyl)furan From

(100,

(13)

solution

to a stirred

stirring

(1001,

Calcd

Found;

(%) 248

gave acetylene13 (II,9 g, 74 %): bp 84-6'C 1.3885; df' 1.348; IR (neat film) 3320, 2138,

'H NMR

cm-';

(CF3 in C-3),

1.600; 6.68

(82).

2-Ethynyl-3,4-bis(trifluoromethyl)furan

mixture

MS m/z

1

kept

H, 0.77.

33.59;

Work-up

and

to the stirred

-11 (4.7 g, 51 %): bp 83-5'C (40 mmHg); nz" 1.4600; diO IR (neat film) 1000 cm-', 'H NMR (Ccl,) 7.54 (-0-CH=), (-C-CH=);

43

of -10 (5.0 g, 37 mmol) and the mixture was

The resulting

temperature

27 ml,

min,

Then, 1 was After

in one portion. further

mixture

-4O"Cinll

for 30 min.

(6.0 ml) was

solution

mmol)

obtained ng"

and G-butyllithium

as similar

1.4336; diO

as above;

(l&j (220mmol), 7.5 g, 67 %: bp

1.430; IR (neat film)

3308,

458 2130, MS

1003

m/z

cm-';

1%)

Anal.

252

Calcd

lff NMR (100,

3.60

1.4240; dj"

'H NMR 19.40

(CC14)

Anal. Found;

1.301; IR (neat film)

3.59 (-C-CH),

Calcd

and n-butyllithium

(CF3);

(%) 160

for C7H3F30;

C, 52.23;

(248 mmol)

6.5 g, 48 %: bp 80-2'C

as above:

MS m/z

(CF3);

19.89

(1_5)

Jl_ (21.2 g, 85 mmol)

gave 15 as similar ng"

"F

H, 0.75.

2-Ethynyl-3-trifluoromethylfuran Furan

(-CZCH);

333 (181, 199 (29). H, 0.80. for C10H2F60; C, 47.64;

C, 47.52;

Found;

(CC14)

M+),

3308,

2118,

(300 mmHg); 995 cm-';

7.37 (-0-CH=),

6.56 (-C-CH=);

(100, M+),

(21), 131

C, 52.52;

141

"F

(35).

H, 1.89.

H, 1.30.

Polymerization. In the thermal

and y-ray

monomer

in an ampoule

melting

procedure,

10-3 mmHg).

the ampoule

The y-ray

2.9 x 105 rad/h Oxidation

at room

diamine

(0.12 g,

CuCl

1.4

temperature

polymerizations

were

at given

the molecular where

calculate

of l4

were

the polymer

Thermal

analyses

Electronics

Ltd.

Acetylenes generated

were

the calibration the molecular

freezing

and

vacuum

(ca.

under

carried

out by

for given

were

carried

time

(see

out at

To a mixture

of -14 and tetramethylene

(0.10 g, 1.0 mmol)

mmol)

weights

the

temperature.

in acetone

for 30 min to afford

the conversions since

temperature

polymerizations

In the oligomerizations

GPC,

by a successive sealed

polymerization 4.0 mmol),

polymerizations,

was

induced

(1.0 g, room

was degassed

and the ampoule

The thermal

maintaining text).

induced

(10

ml) was

the polymer

bubbled

02 at

(55 % yield).

of -13 and 15, the conversions and estimated by a Toyo Soda HLC-8024A curve

weights.

for polystyrene

was

used

In the polymerization

estimatedbya

to

of 14,

IRabsorptionat3308

cm-',

of -14 was insoluble in organic solvents. were carried out by a Seiko Instrument & TG 20 type.

-13 and -15 hardly

by UV irradiation

polymerized

to w(C0)6

in CC14

with

[Il.

the catalyst

459

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T. Ueda

and K. Ito, Macromolecules,

18

1634. 2 K. Okuhara,

J. Org.

3 R. J. Kern,

J. Polym.

4 I. Nomatsu

Chem. 41 Sci.,

and K. Yumoto,

(1976)

1487.

Part A-l, 1 (1969)

Japanease

Patent

621.

S57-143321;

S57-149326. 5 V.V. Lyalin,

R.V. Grigorash,

L.M. Yagupolskii, 6 K. Okuhara,

Bull.

L.A. Alekseeva

J. Org. Chem. Chem.

Sot.,

USSR, Jpn., 2

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and

(1975) (1981)

1073.

2045.

(1985)