PT100005A - PROCESS FOR THE PREPARATION OF SULFONYL HALETS - Google Patents

Description

Description of the patent application of IMPERIAL CHEMICAL INDUSTRIES PLC, British, industrial and commercial, headquartered at Imperial Chemical House, Millbank, London SW1P 3JF, England (inventor: Gary Neil Sheldrake, resident in England), " PROCESS FOR PREPARATION OF SULFONYL HALETS "

The present invention relates to the preparation of sulfonyl halides. The perhaloalkane sulfonyl halides have been prepared by reacting perhaloalkanes with sodium dithionite following the halogenation of the intermediate sulfonic 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). These methods involve the use of highly volatile per-haloalkanes such as carbon tetrachloride and 1,1,1-tri-chloro-trifluoroethane whose use requires considerable precautions to prevent the escape of these volatile substances into the atmosphere . The present invention describes the process for the preparation of haloalkanesulfonyl halides including the perhaloalkane sulfonyl halides where the use of such volatile substances is avoided.

Accordingly, the present invention provides a process for the preparation of sulfonyl halides of general formula I (hereinafter shown), wherein X, Y and Z represent radicals selected from halogen atoms, preferably chloro, fluoro or bromo and R represents a halogen atom or an alkyl or haloalkyl group, or represents an aryl group which may be optionally substituted with halogen atoms, which process comprises reacting the corresponding sulfonyl halide of general formula II (hereinafter) represented by an oxidizing agent.

Suitable oxidizing agents include, for example, peroxides and peracids such as hydrogen peroxide, peracetic acid and perbenzoic acid.

A preferred oxidizing agent is a mixture of hydrogen peroxide and glacial acetic acid. The process may be carried out at elevated temperatures, if desired.

Compounds of formula I which may be prepared by the process of the present invention include for example: trichloromethanesulfonyl chloride, tribromomethanesulfonyl bromide, trifluoromethanesulfonyl bromide, 1,1-dichloro chloride -2,2,2-trifluoro-ethanesulfonyl chloride, and 1,1-dichloro-1- (4-chloro-phenyl) -methanesulfonyl chloride.

Compounds of formula II which may be oxidized to provide compounds of Formula I by the process of the present invention include, for example: trichloromethanesulfenyl chloride, tribromomethanesulfenyl bromide, trifluoro-methane- sulfenyl, 2

1,1-dichloro-2,2,2-trifluoroethanesulfenyl chloride, and 1,1-dichloro-1- (4-chloro-phenyl) -methanesulfonyl chloride.

The sulfenyl halides of formula II can be obtained by hydrogenolysis of suitable precursors such as a disulfide of formula III (hereinafter) or a thioether of formula IV (hereinafter shown) wherein the halogenation of the methylene group which supports the substituent R is accompanied by hydrogenolysis of the sulfur-benzyl linkage thereby giving a sulfonyl halide of formula II and a benzyl halide. The sulfonyl halides of formula I are valuable chemical intermediates which may be used in the synthesis of chemical compounds. A particularly useful process involves the reaction of sulfonyl halides of formula I with unsaturated esters such as, for example, methyl 3-3-dimethylpent-4-enoate to provide compounds of general formula V (hereinafter) which constitute valuable intermediates for the preparation of pyrethroid insecticides.

Such reactions are well defined and fully described in our copending patent application with the same date entitled " Process for the Preparation of Halogenated Compounds ".

Compounds which may be prepared by reaction of the sulfonyl halides include: methyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, methyl 3,3-dimethyl-4,6,6,6-tetrabromohexanoate, 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, methyl 3,3-dimethyl-4-bromo-6,6,6-trifluorohexanoate, 4,4-dimethyl- 7-pentachloroheptan-2-one, 3,4-dimethyl-1,5,7,7-tetrachloro-7- (4-chloro-phenyl) -heptan-2-one, 3,3-dimethyl-4,6 , 6,6-tetrachlorohexanoic acid, methyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 3.3-dimethyl-4,6,6-trichloro-7,7,7 -trifluoroheptanoate, methyl 3,3,3-dimethyl-4,6,6-trichloro-6- (4-chloro-phenyl) hexanoate, 3.3-dimethyl-4,6,6-trichloro- Benzoyl 7,7-trifluoroheptanoate, 2,6-dichloro-benzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 3,3-dimethyl-4,6 , 4-methyl-2,3,5,6-tetrafluoro-benzyl 6-trichloro-7,7,7-trifluoroheptanoate, pentafluoro-3,3-dimethyl-4,6,6,6-tetrachlorohexanoate -benzyl, 3,3-dimethyl-4,6,6,6 2-methyl-3-phenyl-benzyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 2,3,5,6-tetrafluorobenzyl tetrachlorohexanoate, 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, 3-phenoxybenzyl 3,3-dimethyl-4,6,6-tetrachlorohexanoate, α-cyano-3-phenoxybenzyl, Î ± -cyano-3-phenoxy-benzyl dimethyl-4,6,6,6-tetrabromohexanoate, α-cyano-4-fluoro-3,3-dimethyl-4,6,6,6-tetrachlorohexanoate, 3-phenoxybenzyl, 3.3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate, 3-phenoxybenzyl, 3,3-dimethyl-4,6,6-trichloro -7,7,7-trifluoroheptanoate. Î ± -cyano-4-fluoro-3-phenoxy-benzyl.

Such compounds may be used for the preparation of pyrethroid insecticides, for example, using techniques described in British Patent No. 1520443.

In the following examples are more promising data relating to the process of the present invention. EXAMPLE 1

This example illustrates the preparation of bis- (2,2,2-trifluoro-methyl) disulfide. - 4 -

A mixture of 2,2,2-trifluoroethyl bromide (9.8 g), sodium sulfide monohydrate (14.4 g), sulfur (1.9 g), hexadecyl-tributyl bromide (1.0 g) and water (18.0 g) was charged and introduced into a Carius tube under a nitrogen atmosphere and the tube was then sealed. The tube was heated at 70 ° C for 8 hours, allowed to cool and the contents were distilled in a steam bath to provide bis- (2,2,2-trifluoro-ethyl) disulphide with The title compound was obtained as an oil in 67% yield. The product construction was carried out by gas chromatography (GC) / mass spectroscopy. EXAMPLE 2

This example illustrates the preparation of 1,1-dichloro-2,2,2-trifluoroethanesulfenyl chloride.

Sulphenyl chloride (4.46 g) was added dropwise to a solution of bis- (2,2,2-trifluoro-ethyl) disulphide (1.0 g) in dichloromethane (5.0 cm3) at ambient temperature under nitrogen. a dry nitrogen atmosphere. After 3 hours the desired product was obtained in an estimated 60% yield as verified by gas / liquid chromatography. This product is identical to that obtained in Example 4 described below. EXAMPLE 3

This example illustrates the preparation of 2,2,2-trifluoro-ethyl-thio-methyl-benzene.

A mixture of 1-chloro-2,2,2-trifluoro-ethane (20 g), benzyl mercaptan (12.4 g, 99% purity), sodium hydroxide (22.0 g of a solution 22% aqueous solution) and hexadecyl tributyl phosphonium bromide (0.51 g) was charged to a sealed Carius tube under a nitrogen atmosphere and heated to 70 ° C for 5 hours.

10 hours. The tube was cooled to 0 ° C, the seal was removed, and the contents were separated to yield two layers. The organic layer was collected, washed with water and purified by flash distillation to give 2,2,2-trifluoro-ethyl-thio-methyl-benzene, bp 60-70 ° C / 10 mm Hg, 17.4 g (84% yield, purity 99%). The identity of the product was confirmed by gas chromatography (cg) / mass spectroscopy and by nuclear magnetic resonance comparing with data provided by C. Bunyagidj et al, J. Org. Chem., 1981, 46, 3335 EXAMPLE 4

This example illustrates the preparation of 1,1-dichloro-2,2,2-trifluoroethanesulfenyl chloride.

A solution of 2,2,2-trifluoro-ethyl-thio-methyl-benzene (20.0 g, purity 99%, obtained according to the method of Example 3 previously described) in 1,1,2, 2-tetrachloroethane (26.4 cm 3) and cooled to 0 ° C, and then chlorine in the gaseous state was passed through the solution for about 3 hours at that temperature. The orange solution thus obtained was treated with nitrogen and subjected to fractional distillation to provide the 1,1-dichloro-2,2,2-trifluoro-ethanesulfenyl chloride as a dark yellow oil, mp -65øC / 200 mbar (17.4 g, 73% purity, 60% molar yield) contaminated with residual tetrachloroethane and benzyl chloride at less than 1%. The product was identified by gas chromatography (cg) / mass spectroscopy having been compared with the 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-trichloro-ethanesulfonyl chloride. 6

1,1-Dichloro-2,2,2-trichloroethanesulfenyl chloride (6.3 g) was prepared by the procedure described in the method of Example 4) and dissolved in glacial acetic acid (16.0 g) at temperature of 10 ° C and then the solution was cooled to 5 ° C. Hydrogen peroxide (16.8 g of a 30% solution in water) was added dropwise to the sulfonyl chloride solution for 30 minutes, after which the solution was heated at 60Â ° C until yellow had completely eliminated (about 2 hours). The mixture was allowed to cool to room temperature and the excess hydrogen peroxide was decomposed by treatment of an aqueous solution (10% w / w) of sodium metabisulfite. The mixture was partitioned between two phases and the lower organic layer was collected and analyzed by gas chromatography (cg) / mass spectroscopy. It was found to contain 75% w / w of the desired 1,1-dichloro-2,2,2-trifluoro-ethanesulfonyl chloride compound in a molar yield corresponding to 57%. The identification of the product was confirmed by comparison with the material prepared according to 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-tetrachlorohexanoate.

To a solution of methyl 3,3-dimethyl-pent-4-enoate (8.26 g) in toluene (8.67 g) was added trichloromethanesulfonyl chloride (22.5 g) in the presence of tris- (triphenylphosphinyl) ruthenium (II) (0.2 g) and the mixture was heated under a nitrogen atmosphere to reflux temperature (about 111 ° C) for 40 hours. The composition of the reaction mixture was determined by gas / liquid chromatography (cgl). The present amount of the desired product allowed to determine a yield of 76% by weight taking as. base the charged methyl 3,3-dimethyl-pent-4-enoate compound 7

and a yield of 90% based on the methyl 3,3-dimethyl-pent-4-enoate compound consumed. Identification of this product was confirmed by gas / liquid chromatography (cgl) / mass spectroscopy and by comparison with the results for methyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate obtained by the method described in British Patent No. 1520443. EXAMPLE 7

This example illustrates the preparation of methyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate.

Trichloromethanesulfonyl chloride (44.5 g) was added to a mixture of methyl 3,3-dimethylpent-4-enoate (16.52 g), toluene (17.34 g) and benzoyl chloride (0.563 g) and the mixture was heated at 90 ° C for 3.5 hours. Determination of the composition of the reaction mixture by gas / liquid chromatography indicated that the desired product had been obtained in 92% yield based on the charged methyl 3,3-dimethyl-pent-4-enoate. EXAMPLE 8

This example illustrates the preparation of methyl 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate.

A mixture of 1,1-dichloro-2,2,2-trichloro-ethanesulfonyl chloride (1.5 g) and methyl 3,3-dimethylpent-4-enoate (2.0 g) was heated to The reaction mixture was cooled to 110 ° C for 40 minutes and the composition of the product obtained was determined by gas / liquid chromatography (cgl) analysis. There was thus obtained that the desired product was obtained in 79% yield. 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-trifluoro-ethanesulfonyl chloride (0.2 g) was added to a mixture of methyl 3,3-dimethyl-pent-4-enoate (0.18 g ), toluene (0.13 g) and dibenzoyl peroxide (0.015 g) were added and the mixture was then heated at reflux temperature (about 111 ° C) for 2 hours. Determination of the composition of the resulting reaction mixture demonstrated that the desired product was produced in 82% yield and that there were no longer any

(I)

CHEMICAL FORMULAS (REFERRED TO IN THE DESCRIPTIVE MEMORY)

R-C-SO2-X

Z

Y

I (II)

R_C_S_Z

I z

And and

R-c-S-S-C-R (III)

Z

(IV): CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH

Claims (1)

A process for the preparation of a sulfonyl halide of general formula: X in which the radicals X, Y and Z are selected from halogen atoms and the radical R represents a halogen atom or an alkyl, haloalkenyl or aryl group, which may be optionally substituted with halogen atoms, characterized in that reacting the corresponding sulfenyl halide of the general formula: with an oxidizing agent. A process according to claim 1 wherein the oxidizing agent is selected from peroxides and peracids. 3. A process according to claim 2 wherein the oxidizing agent is selected from hydrogen peroxide, perbenzoic acid. 4. A process according to claim 3, wherein the oxidizing agent is a mixture of hydrogen peroxide and glacial acetic acid. 5. A process according to claim 1 wherein the sulfenyl halide is obtained by hydrogenolysis of a disulphide of the formula: or a thioether of formula R The applicant claims the priority of the British application filed on 11 January 1991 under No. 9100655.1. Lisbon, January 10, 1992 12