Chemistry in hydrogen fluoride V. Catalysts for reaction of HF with halogenated olefins

Journal of Fluorine Chemistry,

13(1979)

7 - 18

7

0 Elsevier Sequoia S.A., Lausanne - Printed in the Netherlands Received: October 19.1978

CHEMISTRY HF

WITH

A. E.

IN

HYDROGEN

HALOGENATED

FLUORIDE

V.

CATALYSTS

FOR

REACTION

OF

OLEFINS*

FEIRING

Central

Research

Experimental

& Development

Station,

Wilmington,

Delaware

Department,

E. I. du Pont de Nemours

& Company

19898

SUMMARY

Tantalum

pentafluoride,

tetrachloride,

and molybdenum

of hydrogen

fluoride

compounds.

Hydrogenation

chloroethane TaF5

was

niobium

pentafluoride,

pentachloride

to tetra-

and

catalyze

trichloroethene

of tetrachloroethene

observed

using

hydrogen,

titanium the addition and related

to 1,1,2,2-tetra-

methylcyclopentane,

and

in HF.

INTRODUCTION The

liquid

is an important compounds. alkenes

1

method

by halogen,

this report,

several

in particular, over

Contribution

proceeds

as tetra-

antimony

2615

Alkenes

employed

or boron

hydrocarbon heavily

substituted

require

a

which catalysts.

Catalyst,

trifluoride.

for this addition

pentafluoride

previously

with

or trichloroethene, -

pentachloride2

to alkenes

of organofluorine

readily

or below.

new catalysts

tantalum

No.

of hydrogen.fluoride

for the synthesis

temperature

such

traditionally

f

addition

The addition

at room

advantages

phase

appears

3

In

are described, to have major

8 RESULTS The

fluorination

two processes:

addition

monofluorinated for chlorine derivatives

heated time

2 and 2.

Catalysts

for this process

of batch

HF catalyst

2

at 75-150"

the mixture

The results

are

of the crude

was

shown

reaction

absorptions

vessel.

in Table mixture

assignable

demonstrated

were

fluorinated screened

>

of the catalyst

After

dried, 1.

highly

of 0.2 mole

appropriate

to 0" and quenched

separated,

the

of fluorine

HF catalyst

A mixture

to 0.018 mole

in a closed

involves

HCC12-CF3

'

experiments.

was cooled

phase

the more

HCC12-CC12F

~--> catalyst

to give

by a series

giving

of HF, and 0.006

experiments

followed

reactions

The organic

only

2

bond

exchange

HCC12-CClF

0.5 mole

(,&I formally

of HF to the double

derivative

CC12=CCl*

in a series

of tetrachloroethene

and

with

by proton

that no reaction

reaction

by glpc.

examination

and fluorine

to the products

was

ice water.

analyzed

In all cases,

of ,$,

nmr showed

in Table occurred

1.

Control

in the absence

of a catalyst. The results in addition

to the previously

for the reaction. active

indicate

Tantalum

of the materials

temperatures inactive.

that TaF5, known

TiC14,

SbC15,

pentafluoride

tested,

as low as 75O where

maintaining antimony

MoF5,

and NbF5,

are active appears

catalysts

to be the most

its activity pentachloride

to was

9 Table

1

Addition

of HF to Tetrachloroethylenea

Catalystb (mole %)

c

Product Analysisd J. 2, 2

6.

TaF5

(9)

1500

24.9 g

3

4

93

-

TaF5

(2.5)

150"

27.3 g

1

3

94

2

TaF5

(9)

7s"

30.3 g

30

40

30

-

SbC15

(3)

150"

24.6 g

48

21

30

-

SbC15

(9)

750

28.7 g

100

-

-

-

TiC14

(9)

1500

25.9 g

47

42

11

-

MoC15

(9)

150°

22.8

32

53

16

-

1500

29 4

61

34

4

-

NbF5 a.

Product Weight

Temperature

(51

0.2 mole

CC12=CC12;

percent

0.5 mole

HF; 6 hr.

b.

mole

C.

crude

d.

by glpc using a 10 ft x 0.25 in.lO% operated at 60°.

product

Under TaC15,

no catalytic

scale

an 86% yield

150".

at 150'

experiment

was

TaF5

Trichloroethene

tetrachloroethene, successful

fluorination.

the olefin

to a stirred

column

HgO,

BF3,

and WC1 6 showed reaction. 6) using

A

TaF5

gave

,J. of additional

are

(,5), a more

shown

in Table

sensitive

somewhat

solution

halogenated

to a mixture

were

of TaF5

HCl generated

2.

Fluorotri-

of ,$ and $ at

molecule

different

Best results

(5-25O).

and filtering.

experiments,

for the addition

converted

required

batch

(Table 2, entry

catalysis

smoothly

drying,

carbowax

NbC15,

on the fluorination

using

low temperatures

with water,

of these

of pure distilled

Results

chloroethene

washing

V 0 ZrC14, 2 5'

CoF3,

activity

preparative

on CC12=CC12.

after

the conditions

Ta205,

compounds

based

g

than

conditions

achieved

for

by adding

in HF at relatively in the reaction

must

be

2

(0.08)

(0.8)

(0.3)

CC12=CHC1

CC12=CHC1

CC12=CHCl

Isolated

yield

(0.2)

HCC12CC12H

a.

(0.2)

CH2C1CC1F2

(0.25)

(0.2)

CH3CC13

(0.8)

CC12=CC12

HCC12CC12F

(0.4)

(0.2)

CC1F=CC12

CH2=CC12

(moles)

TaF5

0.5

product,

TaF 5 (0.01)

1.0

based

hr

hr

hr

hr

hr

hr

1500/6

(33)

(trace) HCCl,-CCl,H

H2CCl-CF3

(70)

tar recovered

H2CC1-CF3

(31) (5)

H3C-CC1F2

(80) (10)

(86)

(40)

HCC1=CC12

H3C-CC12F

HCC12-CF3

HCC12-CC1F2

HCC12-CC1F2

tar

H3C-CC12F

recovered

H2CC1-CC12F

charged.

hr

1000/6

7S"/6 hr

1500/6

1500/6

25"/3

25'/17

(89)

(1)

(40)

H2CC1-CC12F H2CC1-Ccl3

(32)

hr H2CC1-CClF2

HCC12-CF3

(75) (15)

(%)a

HCC12-CC1F2

Product

5O/2.5 hr H2CCl-CC12F

25'/0.5

150"/6

on substrate

(0.018)

(0.0075)

TaF5

0.25

(0.018)

(0.02)

(0.01)

TaF5

TaF5

TaF5

(0.015)

(0.008)

(0.002)

(0.018)

(moles) Conditions

0.25

2.0

0.5

BF3

TaF5

1.0

0.5

TaF5

TaF5

Catalyst

0.25

0.5

HF, moles

of distilled

Reactions

Substrate

Fluorination

Table

(50)

(60)

11 vented

to prevent

HCl addition conditions were

product,

quite

obtained.

the catalyst

of substantial

good

boron

yields

products

under

more

Ts>

unreacted

somewhat

gave

only

of the

Under

of fluorinated

trifluoride3

being

quantities

1,1,1,2-tetrachloroethane.

In contrast,

the remainder

HCC1=CC12

formation

,$ and 2

severe

a 33% yield

conditions,

oE ,Q with

5. %

H2CC1-CC12F

&>

H2CCl-CClF2

5 25O

$+

5

2

these

5

$

5

H2CCl-CF3 R

Vinylidene

chloride

yield

treated

when The

TaF5/HF

gave with

converted

TaF5

fluorination

was briefly cleanly

chloroethane

were

l,l-dichloro-l-fluoroethane and 1.25

of several

explored

saturated

under

substrate

when

In view

treated

medium

pressures TaF5/HF Reaction potential

a brief

relatively

was conducted.

in acid

the conditions

in the presence

The presence

hydride

donor,

resulted

conditions.

catalyzed

unreacted

hydrogena-

of & in the

of hydrogen

on the reaction

of the first

of 0.2 mole

2 was

tars plus

on the reduction

up to 5000 psi had no effect under

usi.ng

at 150'.

interest

study

mild

gave mainly

TaF5/HF

of the recent

4-7 tion reactions, TaF5/HF

with

halocarbons

Both 1 and l,l,l-tri-

to ,$ and $ at 150". fluorinated

of HF at 25'.

As expected,

(Table 2).

1,1,2,2-tetrachloroethane

However,

equivalents

in 40%

entry

at of & with

in Table

1.

of methylcyclopentane,

only

in,conversion

of the

a

12 hydrocarbon heating

to cyclohexane;

a mixture

(5000 psi) products

IIF (0.5 mole),

methylcyclopentane

(0.1 mole),

and hydrogen

traces

2, or 4. ?,

isolated

ethane,

was recovered

However,

(0.2 mole),

gave only

$

unchanged.

of tetrachloroethene

(0.018 mole),

TaF5

~ 1 was recovered

of unreacted

The major

in 30% yield

essentially

product

based

$ andthe

fluorination

was 1,1,2,2-tetrachloroThe methylcyclopentane

on $.

unchanged.

DISCUSSION The addition to involve

protonation

resulting

cation

probably

stems

capable The

of hydrogen

acceptors is well

of

'super-acid'

sequence

basic

systems

pentahalides

highly

from HF and

of the

species

olefins. fluoride

and tantalum

exchange

(Scheme

e.g.,

L$ and 2, is more

process

1) could

formation

ion

pentafluoride

account

difficult

for the observed

exchange 2l e

of more

highly

to define.

and an elimination-addition

HCC12-CC12F

HCC12-CC1F2 exchange

2 i CC12=CF2

acidic

halogenated

1

CC12=CClF

by capture

of this process

of more

of the subsequent

products,

Both a direct

followed

is likely

8

The mechanism fluorinated

to olefins

Catalysis

the weakly

such as antimony known.

1

the formation

of protonating

formation

Scheme

of the olefin

by fluoride.

from

fluoride

HCC12CF3 4.

results.

13 The conversion of ,$ to 2 is a catalyzed process as no reaction occurs when $ is treated with HF alone at 150'. several mechanisms for this catalysis can be proposed

A priori_,

(Scheme 2).

Pathway a is a ligand exchange process which has previously been proposed' for antimony halide catalyzed fluorination reactions. Scheme 2 HCC12-CC12F

HCC12CF2Cl

Pathway b involves an acid catalyzed loss of chloride generating a carbocation which can form product through the olefin (pathway c) or directly by fluoride ion capture

(pathway d).

The requirements

for any active catalyst for these processes should differ.

The

effectiveness of a catalyst for the direct exchange process (pathway a) should depend in part on the lability of its ligands and the concentration of coordinately unsaturated species in solution.

Pathway b requires the catalyst to generate a Species

sufficiently acidic to protonate 2.

In principle, a comparison

14 of the efficiency study

for the & ->

process

could

plicated

largely

by the question

from

10

decrease

its activity

in superacid produced

of the now well

Interestingly,

by protonation

of donating

reduced

hydride

compared

to Sb(II1)

with

is known5

to

catalyst.

4-6

reduction

is

of carbocations

the cation

of ,& is not directly in the presence

from a tertiary

to that of delocalized of aromatic

known

In

here may derive

to reduction6

of Sb(V)

is com-

lifetimes.

observed

2

possibilities

of 1; to 1,1,2,2-tetrachloroethane

media.

is efficiently

to the 2 ->

mechanistic

catalyst

as a fluorination

The reduction example

resistance

in this

from this study

of TaF5

Reduction

halides.

on these

of relative

its greater

identified

compared

of data

performance

antimony

another

information

interpretations

the superior

catalysts

2 transformation

provide

Unfortunately,

fact,

of the various

reduced

of a hydrocarbon

position,

carbocations

by H2, but

formed

behavior

capable similar

by the protonation

4

hydrocarbons.

EXPERIMENTAL Hydrogen

fluoride

(Alfa), niobium (Fisher),and received. inert

samples

pentafluoride

molybdenum

Antimony

atmosphere used

(Air Products),

pentachloride

pentachloride

before

use.

as received.

A-60

instrument

Fluorine

NMR spectra

operated

at 94.1 MHz using obtained

reagents

NMR spectra with

obtained CFC13

tetrachloride

(Alfa) were

All other

in CDC19

were

titanium

pentafluoride

used

as

(B & A) was distilled

Proton

a Varian

data were

(Alfa),

tantalum

were

as internal 5700A

commercial

obtained

TMS as internal

on a Varian

on a Hewlett-Packard

were

in an

XL-100

on

standard. instrument

standard. instrument.

Glpc

15 Caution! human

tissue,

Laboratory

Hydrogen

contact

work

hood with

resulting

with

operator

fluoride

IIF should

wearing

full

is extremely

in painful,

corrosive

slow-healing

be conducted

only

face shield

to burns.

in an efficient

and protective

clothinq.

Catalyst

Screen

An 80-ml (0.2 mole)

Hastelloy

of tetrachloroethene

The bomb was cooled charged

with

10 g

to atmospheric for six hours was cooled

in dry

pressure with

over

organic

parison with

layer

anhydrous

analyzed

flow of 60 ml/min.

Preparation

(0.8 mole)

Hastelloy

bomb

of tetrachloroethene

pentafluoride. evacuated,and

15ooc.

with

The

against

was agitated

with

40 g

for 6 hr with

The bomb was cooled

and

com-

gas

in Table

1.

(2)

with

132.8

g

of tantalum

ice and acetone,

of hydrogen

an inside

in ice water.and

dried

column

carrier

and 5.6 g (0.02 mole)

(2 mole)

The

authentic

tube was charged

in dry

onto

was weighed

in 10% Carbowax

are contained

bomb was cooled

charged

The bomb

water,and

of 1,2,2-Trichloro-l,l-Difluoroethane

A 360-ml

was agitated

the bomb.

of 60°C and a helium results

and brought

discharged

The material

a 10 ft x 0.25

The

evacuated,and

were

washed

33.2 g

of the catalyst.

of 150°C.

to rinse

chromatography

temperature

mole

The bomb

and the contents

chloride.

with

fluoride,

temperature

was collected,

using

0.018

nitrogen.

40 ml of water

by gas liquid

an oven

and

of hydrogen

an inside

calcium

samples

The bomb

with

in ice water

tube was charged

ice and acetone,

(0.5 mole)

30 g of ice, using lower

bomb

fluoride.

temperature the contents

of were

16 discharged onto 50 g of ice using 15 ml of water to rinse the bomb.

The lower organic layer was separated, washed with water,

and dried over calcium chloride.

It weighed 126.5 g.

A

115.6-g portion of the product was distilled at atmospheric pressure to give 104.6 g (0.675 mole, 84%) of 1,2,2-trichloro1,1-difluoroethane as a colorless liquid, bp 70-72'C; proton NMR (6, CDC13) 5.85 (t, J = 5.3 Hz): fluorine NMR (6, CDC13) -63.31 (d, J = 5.3 Hz).

Preparation of 1,1,2-Trichloro-1-Fluoroethane A 250-ml polychlorotrifluoroethylene

C,$,)

vessel was charged

with 2.2 g (0.008 mole) of tantalum pentafluoride.

The vessel

was evacuated, cooled in liquid N2 and ch,arged by distillation with 20 g (1.0 mole) of hydrogen fluoride.

The vessel was filled

with nitrogen and immersed in a bath of water and ethylene glycol at 5OC.

Trichloroethene

added in one portion. 2.5 hr.

(108 g, 0.8 mole), cooled to OOC, was

The resulting mixture was stirred for

The mixture was poured over 40 g of cracked ice.

The

organic layer was separated, washed with water, and dried over anhydrous calcium chloride. chloro-l-fluoroethane

It weighed 116.7 g.

1,1,2-Tri-

(108.1 g, R9%), bp 87-89OC,was obtained

by distillation: proton NMR (6, CDC13) 4.13 (d, J = 13 Hz)

Hydrogenation of Tetrachloroethene An 80-ml Hastelloy bomb tube was charged with 33.2 g (0.2 mole) of tetrachloroethene, 8.4 g (0.1 mole) of methylcyclopentane,and 2.8 g (0.01 mole) of tantalum pentafluoride. The bomb was cooled in dry ice and acetone, evacuated and charged with 10 g (0.5 mole) of hydrogen fluoride.

The bomb was warmed

to 25' and pressured to 5000 psi with hydrogen.

The bomb was

agitated for 6 hr with an inside temperature of 150°C.

The

bomb was cooled to O0 and vented slowly to atmospheric pressure. The contents were discharged onto 40 q of ice.

The lower organic

layer was collected, washed with water,and dried over anhydrous calcium chloride.

Evaporative distillation of the material at

2 mm to a vessel cooled in dry ice gave 19 q of colorless liquid, separating it from a quantity of tar.

Proton NMR of the liquid

showed upfield absorption for methylcyclopentane and a singlet at 6 5.95 for 1,1,2,2-tetrachloroethane.

Glpc analysis of

the material against authentic samples using a 10 ft x 0.25 in 10% carbowax column with an oven temperature of 50' confirmed the above products.

The chromatoqraph also showed traces of

&I 51 and 2.

REFERENCES

W. A. Sheppard and C. M. Sharts,

'Organic Fluorine

Chemistry,' W. A. Benjamin, Inc., New York (19691, pages 59-65. M. R. Frederick, U.S. Patent 2,724,004 (Nov. 15, 1955); E. T. McBee, U.S. Patent 2,637,747 (Jan. 23, 1948). R. C. Arnold, U.S. Patent 2,560,838 (July 17, 1951); A. L. Henne and R. C. Arnold, J. Amer. Chem. Sot. 70, 758 (1948). J. Wristers, J. Chem. Sot. Chem. Commun., 575 (1977). H. Hoqeveen, C. J. Gaasbeek, and A. F. Bickel, Rec. Trav. Chim. Pays-Bas 88, 703 (1969); H. Hoqeveen and A. F. Bickel, ibid, 88, 719 (1969).

18 6

M. Siskin

and J. Porcelli,

(1974); M. Siskin, 98,

5413

A. E. Feirinq,

8

M. Kilpatrick

Press,

ibid.=,

3641

Chem.

Sot. 96,

(1974); M. Siskin,

3640 ibid

(1976).

7

Aqueous

J. Amer.

J. Org. Chem. and J. G. Jones

Solvents,' New York,

9

Reference

10

M. Herlem,

42,

J. J. Laqowski 1967,

1, pages Pure

in

Chapter

3255

(1977).

'The Chemistry ed.,

Vol.

2.

76-81.

Appl.

Chem.

49, 107

(1977).

of Non-

II, Academic