CS211397B2 - Method of making the derivatives of the 2,2-difluor-1,4-benzodioxen - Google Patents

Description

The invention relates to a process for the preparation of novel 2,2-difluoro-1,4-benzodioxene derivatives which can be used as starting materials for the preparation of insecticidally active benzyl esters containing ether and thioether residues which are are substituted with fluorine.

SUMMARY OF THE INVENTION The present invention provides a process for the preparation of 2,2-difluoro-1,4-benzodioxene-1 derivatives of formula (I) by halogen, optionally substituted by phenyl or phenoxy, cairbonyl, nitro, cyano, SO 2 H, or two of these residues represents a fused benzene ring, and

X ^{1 is} hydrogen or halogen by reacting compounds of formula II,

(II) wherein n is 1 to 4 and

R ^{1 has} the same or- different radicals from the group forms-en-is hydrogen, alkyl having 1 to 6 carbon atoms, fluoroalkyl having 1-6 carbon atoms and 3-6 fluorine atoms, alkioxy & kupinoiu having 1 to 6 carbon atoms, halogenalkoxyskupimoiu and 1 to 6 carbon atoms and 1 to 6 halogen atoms, an alkylmercapto group having 1 to 6 carbon atoms, a haloalkylmercapto group having 1 to 6 carbon atoms and 1 to 6 halogen atoms, an alkenyl group having 2 to 6 carbon atoms, (C 2 -C 6) alkynyl;

R ¹ and n are as defined above, with compounds of formula III,

FX ¹

(III) wherein X ^{2 is} halogen, and X ^{1 is} hydrogen or -halogen.

If 4-methylpyrocatechinium and trifluorochlorethylene are used as starting materials, the reaction scheme can be illustrated as follows:

CH.

OH + F.C-CCIF OH

The starting materials are preferably pynocatechin of formula II in which R @ ¹ represents the same or different radicals from the group consisting of hydrogen, C1 -C4 alkyl, in particular methyl, ethyl, tert-butyl, fluorine, chlorine, bromine. or C1 -C4 alkyl, in particular methyl, halogen, especially chlorine, bromine, substituted phenyl, carboxyl, nitro, cyano, sulfo, or two of these together with adjacent carbon atoms form an unfused benzene ring.

The following compounds of formula II may be mentioned individually: pyrocatechin,

- methylpyrokateehin,

4-methylpyrocatechin,

4-tert-butylpyirocatechin,

4-chloropyrocatechin,

4-brbmpyrocatechin,

3.5- dichloropyrokateehm,

4.5- dichloropyrocatechin,

3.4.5- trichlorpyroikateehin, tetraehlorpyrocatechin,

3,4-dihydroxybiphenyl,

2.3- naphthalenediol,

4-methyl-5-chloropyrrocatechin,

4-methyl-3,5,6-trietharpyrakateine,

2.3- dihydroxybenzoic acid,

3.4- dihydroxysulfonic acid, 4-nitrocrocatechium,

4-cyanopyrocatechin,

2,3-diihydrioixylterephthalic acid.

Examples of compounds of formula III are:

chlorotrifluoroethylene, tetrafluoroethylene, bromo trifluoro ethylene, chlorodifluoroethylene, 1,1-dichloro-2,2-difluoroethylene, bromodifluoroethylene.

Chlorotrifluoroethylene and chlorodifluoroethylene are particularly preferred.

Suitable bases are especially ^one alkali metal hydroxides and alkaline earth metals, as well as being useful carbonates of these metals. Their amount may vary between one and more than 3 moles per 1 mol of pyrocatechin. Excess positively affects the reaction. The reaction may be carried out at temperatures of from 20 to 150 ° C, particularly preferably from 80 to 120 ° C. Polar liquids are used as solvents. Examples include:

dimethylsulfoxide, dimethylformamide and tetramethylenesulfone, but ethers such as; dioxane or diethylene glycol dimethyl ether. Tetiramethylene sulfone is preferred.

The reaction is carried out at atmospheric pressure or at elevated pressure to prevent escape of fluorinated ethylene when it does not react immediately upon addition. The process is generally carried out at pressures of from 1 to 3 MPa, preferably between 1 and 1.5 MPa.

The process can be carried out at 0.1 MPa as follows:

A reaction vessel was charged with catechol dissolved in a solvent, adding a base, and stirring the mixture is heated to reaction temperature (e.g. 100 ^Q CJ. After half an hour is then introduced fluorinated ethylene in such an amount that they can be absorbed in the reaction Unreacted olefin leaving the end of the reaction may be recovered to the reaction, operating at elevated pressure, then introducing the pyrocatechin, base and solvent of the pressure vessel, heating the contents to the reaction temperature, and by means of a pump, the ethylene of formula II is supplied at a rate to adjust the desired pressure.

After completion of the reaction, the reaction mixture is worked up either by fractional distillation or by dilution with water and separation of the reaction product.

The following examples illustrate the process according to the invention.

Example 1

2,2-Difluoro-1,4-benzodiOxene

110 g of pyrocatechin are introduced together with 70 g of potassium hydroxide in 300 ml of tetramethylene sulfone and the mixture is heated at 100 ° C for 30 minutes. 140 g of 1,1-difluoro-2-chloroethylene (which takes about 3 hours) is introduced at a temperature of 100 to 110 ° C. Then, at 2000 Pa, the product is distilled through a small column into a well cooled receiver. It is heated up to an internal temperature of 100 ° C. The contents of the template are transferred to a separatory funnel and the organic phase is separated from the aqueous phase. There were obtained 112 g, i.e. about 65%, the difluoro-2,2, rl, 4-benizodioxanu of refractive index n _D ²⁰ = 1.4802, which is in gas' chiromatoigramu cloth.

Example 2

B-methyl-5S-trifluoro-1H-benzodiioxene

124 g of 4-methylpyrocatechia were introduced together with 110 g of potassium hydroxide in

Tetranietiiylensuifonu 300 ml at 100 ^C centigrade. 170 g of trifluorochlorethylene are then introduced into the flask over 4 hours. The reaction mixture was then distilled through a column at 2000 Pa, collecting a fraction of up to 85 ° C. After separation of the aqueous phase in the receiver, the product is distilled again. Boiling point 70-72 ° C / 1600 Pa (n _D ²⁰ = 1.4565) gives 133 g, i.e. about 65%, of the theory of 6-methyl-2,2,3-trifluoro-1,4-benzodioxene.

Example 3

2,2,3-Trifluar-1,4-benzodioxene

220 ml of pyrocatechin and 130 g of sodium hydroxide are introduced into 600 ml of tetramethylene sulphate at a temperature of 95 DEG to 105 DEG C. and 330 g of trichlorethylene are introduced under stirring at this temperature. Thereafter, the reaction mixture is distilled at 2000 Pa through a column and the fraction boiling at 20 to 60 ° C / 2000 Pa is collected, in a well cooled batch. After separation of the aqueous phase, 332 g of pure 2,2,3-trifluoro-1,4-benzodtoxene remained, b.p. Refractive index n _D ²⁰ = 1.4525.

Yield: 87%.

Example 4

2.2.3-Trifluoro-5,7,8-trichloro-6-chloromethyl-1,4-benzodioxene 6-Methyl-2,2,3-trifluorobenzene-dioxane is introduced together with 1 g of ferric chloride, introduces chlorine. The temperature is allowed to rise slowly up to 80 ° C and chlorinated further until saturation. After distilling off a small proportion of the top fraction distilled at 120 to 125 ^Q C / 20 mm Hg 71 g of product, mp 86 ° C.

Example 5

2.2.3-Trifluoro-6-hydroxy-cyanomethyl-1,4-benzodioxene Hexamethylenetetramine was heated in 50 mL of water to 100 ° C and then, 40 g of 6-chloromethyl-2,2,3-trifluorobenzodioxene was added dropwise. After 1 hour at 100 ° C, 100 ml of water and 100 ml of concentrated hydrochloric acid were added and the reaction mixture was stirred at 100 ° C for 2 hours. Subsequent steam distillation gave 20 g of 6-formyl-2,2,3-tirifluoro-1,4-beinsodioxene, bp 119-120 ° C / 2000 Pa. Refractive index n _D ²⁰ = 1.5001.

Claims (1)

SUBJECT A process for the preparation of 2,2-difluoro, R-1,4-benzodioxene derivatives of the formula I wherein n is 1 to 4 and R ¹ identical or · different radicals from the group consisting of hydrogen, alkyl having 1 to 6 carbon atoms, ftuoralkylovou group having 1-6 carbon atoms and 3-6 fluorine atoms, alkoxy having 1 to 6 carbon atoms, halogenoalkoxy having 1 to 6 carbon atoms of up to 6 halogen atoms, alkylmercaptoscyclic groups of 1 to 6 carbon atoms, haloalkylmercapto groups of 1 to 6 carbon atoms and 1 to 6 halogen atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, halogen, optionally substituted phenyl or phenoxy, carbonyl, nitro, cyano, Invention, the groups SO 3 H, or two of these radicals represent a fused benzo ^ring, X1 is hydrogen or halogen, characterized in that reacting a compound of formula II wherein R 1 and n are as defined above with compounds of formula III, FX ¹ (ΙΠ) in which it means X ² halogen a X ^{1 is} hydrogen or halogen. Severography, n. P ,, plant 7, Most