WO1992012125A1

WO1992012125A1 - Preparation of sulphonyl halides

Info

Publication number: WO1992012125A1
Application number: PCT/GB1992/000038
Authority: WO
Inventors: Gary Neil Sheldrake
Original assignee: Zeneca Limited
Priority date: 1991-01-11
Filing date: 1992-01-08
Publication date: 1992-07-23
Also published as: AU1160992A; PT100005A; GB9100655D0; TW215432B; GB9200266D0; CN1063868A; GB2251619A

Abstract

A process for preparing sulphonyl halides of formula: RCY(Z)SO2?X where X, Y and Z are halo and R is alkyl, halo, haloalkyl or aryl wherein a sulphenyl halide of formula RCY(Z)SX is subjected to oxidation. The sulphonyl halides are useful intermediates for insecticides.

Description

PREPARATION OF SULPHONYL HALIDES

This invention relates to the preparation of sulphonyl halides.

Perhaloalkanesulphonyl halides have previously been prepared by reaction of perhaloalkanes with sodium dithionite followed by halogenation of the intermediate sulphonic acids as described by W. Huang et al, Huaxue Xuebao, 1986, 44(1), 45-50 (Chemical Abstracts, 105, 171793b) and W. Huang et al, Huaxue Xuebao, 1984, 42 *10), 1114-1115 (Chemical Abstracts, 102, 78313g). Such methods involve the use of highly volatile perhaloalkanes, such as carbon tetrochloride and 1,1,1,-trichlorotrifluoroethane, and this requires considerable precautions to avoid escape of such volatile materials to the atmosphere.

The present invention relates to a process for preparing haloalkane sulphonyl halides, including perhaloalkane sulphonyl halides which avoids the use of these volatile materials.

Accordingly the present invention provides a process for the

preparation of sulphonyl halides of formula I:

wherein X, Y and Z are each selected from halo, preferably chloro, fluoro or bromo, and R is halo, alkyl or haloalkyl, or aryl which may optionally be substituted with halo, which comprises reacting the corresponding sulphenyl halide of formula II:

with an oxidising agent.

Suitable oxidising agents include, for example, peroxides and

peracids, such as hydrogen peroxide, peracetic acid and perbenzoic acid.

A preferred oxidising agent is a mixture of hydrogen peroxide and glacial acetic acid. The process can be conducted at elevated temperatures if desired.

Compounds of formula I which can be prepared by the process of this invention include, for example:

trichloromethane sulphonyl chloride,

tribromomethane sulphonyl bromide,

trifluoromethane sulphonyl bromide,

1,1-dichloro-2,2,2-trifluoroethane sulphonyl chloride, and

1,1-dichloro-1-(4-chlorophenyl) methane sulphonyl chloride.

The compounds for formula II, which may be oxidised to obtain the compounds of formula I by the process of the invention, include for example:

trichloromethane sulphenyl chloride,

tribromomethane sulphenyl bromide. trifluoromethane sulphenyl bromide,

1,1-dichloro-2,2,2-trifluoroethane sulphenyl chloride, and

1,1-dichloro-1-(4-chlorophenyl) methane sulphenyl chloride.

The sulphenyl halides of formula II may be obtained by the

halogenolysis of suitable precursors, such as a disulphide of formula III: or a thioether of formula IV:

wherein halogenation of the methylene group bearing the R group is accompanied by halogenolysis of the sulphur-benzyl bond giving rise to the sulphenyl halide of formula II and benzyl halide.

The sulphonyl halides of formula I are valuable chemical intermediates which may be used in chemical synthesis. One particularly useful process involves reaction of the sulphonyl halides of formula I with unsaturated esters, such as for example, methyl 3,3-dimethylpent-4-enoate, to prepare compounds of formula V:

which are valuable intermediates for pyrethroid insecticides. These reactions are set forth and fully described in our copending patent application of even data entitled "Process for Preparing Halogenated

Compounds".

Compounds which can be prepared by reaction of the sulphonyl halides include:

methyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate,

methyl 3,3-dimethyl-4,6,6,6-tetrabromohexanoate,

ethyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate,

methyl 3,3-dimethyl-4-bromo-6,6,6-trifluorohexanoate,

4,4-dimethyl-1,5,7,7,7-pentachloroheptan-2-one,

4,4-dimethyl-1,5,7,7-tetrachloro-7-(4-chlorophenyl)-heptan-2-one,

3,3-dimethyl-4,6,6,6-tetrachlorohexanoic acid,

methyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate,

ethyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate,

methyl 3,3-dimethyl-4,6,6-trichloro-6-(4-chlorophenyl)-hexanoate,

benzyl 3, 3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate,

2,6-dichlorobenzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 4-methyl-2,3,5,6-tetrafluorobenzyl 3, 3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate,

pentafluorobenzyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate,

2,3,5,6-tetrafluorobenzyl 3,3-dimethy1-4,6,6,6-tetrachlorohexanoate,

2-methyl-3-phenylbenzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 3-phenoxybenzyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate,

α-cyano-3-phenoxybenzyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, α-cyano-3-phenoxybenzyl 3,3-dimethyl-4,6,6,6-tetrabromohexanoate,

α-cyano-4-fluoro-3-phenoxybenzyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, α-cyano-3-phenoxybenzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, and

α-cyano-4-fluoro-3-phenoxybenzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate.

Such compounds can be used to make pyrethroid insecticides by, for example, the techniques described in UK Patent No. 1520443.

Further details of the process of the invention are given in the Examples which follow.

EXAMPLE 1

This Example illustrates the preparation of bis-(2,2,2-trifluoromethyl) disulphide.

A mixture of 2,2,2-trifluoroethyl bromide (9.8g), sodium sulphide nonahydrate (14.4g), sulphur (1.9g), hexadecyl tributyl phosphonium bromide (1.0g) and water (18.0g) was charged to a Carius tube under a nitrogen atmosphere and the tube sealed. The tube was heated to 70°C for 8 hours, cooled and the contents subjected to steam distillation to give

bis-(2,2,2-trifluoroethyl) disulphide as an oil in a yield of 67°C. The product was identified by GC-mass spectroscopy.

EXAMPLE 2

This Example illustrates the preparation of 1,1-dichloro-2,2,2-trifluoroethane sulphenyl chloride.

Sulphenyl chloride (4.46g) was added dropwise to a solution of bis-(2,2,2-trifluoroethyl) disulphide (1.0g) in dichloromethane (5.0cm³) at the ambient temperature under a dry nitrogen atmosphere. After 3 hours the yield of the desired product was estimated at 60% by gas-liquid

chromatography. The product was identical to that obtained in Example 4 below.

EXAMPLE 3

This Example illustrates the preparation of 2,2,2-trifluoroethylthiomethylbenzene.

A mixture of 1-chloro-2,2,2-trifluoroethane (20g), benzyl mercaptan (12.4g,

99% strength), sodium hydroxide (22.0g of a 22% aqueous solution) and hexadecyl tributyl phosphonium bromide (0.51g) was charged to a resealable

Carius tube under a nitrogen atmosphere and heated at 70ºC for 10 hours. The tube was then cooled to 0°C, unsealed and the contents separated into two layers. The lower organic layer was collected, washed with water and purified by short path distillation to give 2,2,2- trifluoroethylthiomethylbenzene, b.p. 60-70°C/ 10 mmHg, 17.4g (yield 84%, strength 99%). The identity of the product was confirmed by gc-mass spectroscopy and nuclear magnetic reconance, and by comparison with data provided in C. Bunyagidj et al, J Org. Chem. , 1981, 46 3335.

EXAMPLE 4

This Example illustrates the preparation of 1,1- dichloro-2,2,2-trifluoroethane sulphenyl chloride.

A solution of 2,2,2-trifluoroethylthiomethylbenzene (20.0g, strength

99%, obtained by the method of Example 3 above) in

1,1,2, 2-tetrachloroethane (26.4cm³) was cooled to 0°C and chlorine gas passed into the solution for ca 3 hours at this temperature. The orange solution thus obtained was sparged with nitrogen and subjected to

fractional distillation, to give 1,1-dichloro-2,2,2-trifluoroethane sulphenyl chloride as a deep yellow oil, b.p. 63-65°C/ 200 mbar (17.4g, 73% strength, 60% molar yield) contaminated with residual tetrachloroethane and

<1% benzyl chloride). The product was identified by gc-mass spectroscopy, and comparison with data provided by H. Fritz et al, Chem, Ber., 1989, 122,

1757.

EXAMPLE 5

This Example illustrates the preparation of 1,1-dichloro-2,2,2-trichloroethane sulphonyl chloride.

1,1-Dichloro-2,2,2-trichloroethane sulphenyl chloride (6.3g) obtained by the method of Example 4) was dissolved in glacial acetic acid (16.0g) at 10°C and the solution cooled to 5°C. Hydrogen perodide (16.8g of a 30% solution in water) was added dropwise to the solution of the sulphenyl chloride over 30 minutes after which the solution was heated to 60°C until the yellow colour had been completely discharged (ca 2 hours). The mixture was cooled to the ambient temperature and the excess hydrogen peroxide decomposed by treatment with an aqueous solution (10% w/w) of sodium metabisulphite. The mixture separated into two phases and the lower organic layer was collected and analysed by gc-mass spectroscopy. It contained 75% w/w of the desired 1,1-dichloro-2,2,2-trifluoroethane sulphonyl chloride, indicating a molar yield of 57%. The product identify was confirmed by comparison with material prepared by the method of

H.Wei-Yuan et al, Acta Chim. Sinica, 1986, 44 45 (Chemical Abstracts 105, 171793b) .

EXAMPLE 6

This Example illustrates the preparation of methyl

3,3-dimethyl-4,6,6,6-tetrachl-rohexanoate.

Trichloromethane sulphonyl chloride (22.5g) is added to a solution of methyl 3,3-dimethylpent-4-enoate (8.26g) in toluene (8.67g) in the presence of tris-(triphenylphosphinyl)ruthenium(II) dichloride (0.2g) and the mixture heated under an nitrogen atmosphere at the reflux temperature (ca. 111°C) for 40 hours. The composition of the reaction mixture was then determined by gas liquid chromatography (glc). The desired product was present in an amount indicating a yield of 76% by weight based on methyl 3,3-dimethylpent-4-enoate charged, and 90% based on methyl

3,3-dimethylpent-4-enoate consumed. The identify of this product was confirmed by glc-mass spectroscopy and 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate obtained by the method described in UK Patent No. 1520443.

EXAMPLE 7

This Example illustrates the preparation of methyl

3 , 3-dimethyl-4,6,6, 6-tetrachlorohexanoate.

Trichloromethane sulphonyl chloride (44.5g) was added to a mixture of methyl 3,3-dimethylpene-4-enoate (16.52g), toluene (17.34g) and benzoyl peroxide (0.563g) and the mixture heated at 90ºC for 3.5 hours.

Determination of the composition of the reaction mixture by gas-liquid chromatography indicated that the desired product was obtained in 92% yield based on methyl 3,3-dimethylpent-4-enoate charged.

EXAMPLE 8

This Example illustrates the preparation of methyl

3, 3-dimethyl-4, 6, 6-trichloro-7 , 7 ,7-trifluor7heptanoate .

A mixture of 1,1-dichloro-2,2,2-trichloroethane sulphonyl chloride (1.5g) and methyl 3,3-dimethylpent-4-enoate (2.0g) was heated at 110°C for 40 minutes and the composition determined by glc analysis. This indicated that the yield of the desired product was 79%.

EXAMPLE 9

This Example illustrates the preparation of methyl

3,3-dimethyl-4,6,6-trifluoro-7,7,7-trifluoroheptanoate.

1,1-Dichloro-2,2,2,2-trifluoroethane sulphonyl chloride (0.2g) was added to a mixture of methyl 3,3-dimethylpent-4-enoate (0.18g), toluene (0.13g) and dibenzoyl peroxide (0.015g) and the mixture heated at the reflux temperature (ca. 111°C) for 2 hours. Determination of the resultant reaction mixture composition showed that the desired product had been produced to a yield of 82%, and that no sulphonylchloride remained.

CHEMICAL FORMULAE (in description)

R- CH₂- S - CH₂C₆H₅ (IV)

Claims

1. A process for preparing a sulphonyl halide of formula:

wherein X, Y and Z are each selected from halo, and R is halo, alkyl, haloalkenyl or aryl which way optionally be substituted with halo, which comprises reacting the corresponding sulphenyl halide of formula:

with an oxidising agent.

2. The process of claim 1 wherein the oxidising agent is selected from peroxides and peracids.

3. The process of claim 2 wherein the oxidising agent is selected for hydrogen peroxide, peracetic acid and perbenzoic acid.

4. The process of claim 3 where the oxidising agent is a mixture of

hydrogen peroxide and glacial acetic acid.

5. The process of claim 1 wherein the sulphenyl halide

to obtained by the halogenolysis of either a disulphide of formula:

or a thioether of formula:

R- CH₂- S-CH₂C₆H₅