DE1103327B - Process for the preparation of substituted cyclopentadienes - Google Patents

Description

Process for the preparation of substituted cyclopentadienes Es it is known to react alkyl halides with trialkyl phosphites. This creates with exchange of alkyl residues of phosphonic acid esters and alkyl halides (cf.

A. Arbusow, J. Russ. Phys. Chem. Ges., Vol. 38, 1906, p. 687, and G. M. Kosolapoff in Organic Reactions, Vol. VI, 1951, p. 276).

It has now been found that, surprisingly, substitutions were made Cyclopentadienes are obtained when optionally substituted polyhalocyclopentene, which can also be part of a polycyclic compound with at least 3 halogen atoms with tertiary phosphites.

In the event that octachlorocyclopentene and tri-butyl phosphite are used as starting materials, the reaction can be represented by the following equation: The polyhalocyclopentenes which can be used for the process according to the invention can, in addition to the halogen atoms, also contain other substituents, such as alkyl, cycloalkyl, arylalkoxy groups. The polyhalocyclopentene can also be part of a polycyclic compound, as is the case with perchlorindane.

There are also functional derivatives of the polyhalocyclopentene in question, such as polyhalocyclopentenone.

The following polyhalocyclopentene may be mentioned in detail, the are particularly suitable for the process according to the invention: octachlorocyclopentene, Hexachlorodifluorocyclopentene, hexachlorodibromocyclopentene, hexachlorodiiodocyclopentene, Heptachlorocyclopentene, hexachlorocyclopentene, methylheptachlorocyclopentene, n-butylheptachlorocyclopentene, Chloroethylheptachlorocyclopentene, cyclohexylheptachlorocyclopentene and hexachlorocyclopentenone.

In principle, all trialkyl, tricycloalkyl- and triaryl phosphites as well as mixed phosphites. The alkyl, cycloalkyl and aryl groups can also be further substituted by e.g. B. alkoxycarboxylic acid esters and thioether groups. The following tertiary Use phosphites: trimethyl, triethyl, triisopropyl, tri-n-butyl, trioctadecyl, Trichloroethyl, tricyclohexyl, phenyldimethyl, trifurfuryl phosphite and the phosphites of lactic acid ethyl ester, N-ß-Hydroxyäthylacetamids, ß-Hydroxyäthylkresyläthers, of ß-Hydroxyäthylnaphthyläthers, Äthyleneglykolmonomethyläthers and Äthyleneglykolmonoacetats.

To carry out the process, the polyhalocyclopentene, optionally dissolved in inert solvents, submitted and at temperatures between -30 and + 150 ° C the phosphites were added dropwise. However, in some cases it can it should also be indicated to submit the phosphite and, for this purpose, the polyhalocyclopentene to drip.

As inert solvents, for. B. Benzene, aliphatic hydrocarbons, Esters, ethers, such as dioxane, tetrahydrofuran and aliphatic ether, furthermore formamides, such as dimethylformamide, in question.

For 1 mole of polyhalocyclopentene, from 0.5 to 10 moles of tertiary Phosphites are used. Preferably about 2 moles of tertiary phosphite are used.

In most cases, the reaction is very exothermic and in a short time. With low halogen cyclopentene or less reactive phosphites the mixture must be reheated for some time to complete the reaction will. The course of the reaction can be inferred by recording the UV or IR spectrum Samples can be easily tracked.

The reaction mixture is worked up either by distillation, Crystallization, extraction, or chromatography by chemical conversion of the individual reaction products. Solvolysis of the formed has proven particularly useful Phosphoric acid diester halides with compounds containing active hydrogen, such as water, alcohols, ammonia, amines, mercaptans, phenols and thiophenols, and separating the more stable phosphoric acid ester derivatives thus obtained. In the Use of alcoholic phenols and mercaptans is recommended to avoid this of side reactions and to accelerate the reaction itself the addition of hydrogen halide acceptors, such as tertiary bases, alkali and alkaline earth alcoholates, mercaptans or phenolates. In the case of solvolysis with ammonia, primary or secondary amines, these act by themselves as hydrogen halide acceptors. Because of the lability of most polyhalocyclopentadienes against- over alkaline substances should be used when using of alkali or alkaline earth metal hydroxides or organic bases, an excess if possible be avoided and work at a low temperature. The end of the reaction can be determined by titration or processing of a sample.

A preferred embodiment of the work-up is saponification the phosphoric acid diester halides, which are usually readily soluble as alkali salts Phosphoric acid diesters are formed, which can be easily washed out with water.

The products manufactured using this process are mostly new Substances are valuable intermediates for the synthesis of pesticides and plastics can be used. The resulting alkyl, cycloalkyl and aryl halides and the phosphoric acid diester halides or those produced therefrom Phosphoric acid derivatives are of great technical interest.

Example 1 To a solution of 344g (1 mol) octachlorocyclopentene, dissolved in 500 cc of benzene, 500 g (2 mol) of tri-n-butyl phosphite are added dropwise within 2 hours; the temperature of the reaction mixture is kept at 40 bis by cooling 500 C. After the addition is complete, the benzene is distilled together with the butyl chloride on the water bath and hydrolyzes the phosphoric acid dibutyl ester monochloride contained in the residue by boiling for 2 hours with 5000 cc of water. When the hydrolysis is complete, the organic Phase separated and the phosphoric acid dibutyl ester with sodium hydrogen carbonate solution shaken out, leaving about 270 to 280 g of n-butylpentachlorocyclopentadiene, which are purified by distillation, boiling point 12 = 1360C; n2D = 1.5265.

Analysis: Calculated ... C = 36.6%, H = 3, 10! O, Cl = 60.2%, found ... C = 36.80 / 0, H = 3.3%, Cl = 59.9%.

Example 2 To 344 g (1 mol) of octachlorocyclopentene dissolved in 500 cc Benzene, 332 g (2 mol) of triethyl phosphite are added dropwise with cooling at 40 to 500 ° C. to. Then the ethyl chloride (about 60 g) and the Benzene distilled off. The residue is worked up as in Example 1. yield about 250 g of ethyl pentachlorocyclopentadiene, boiling point 14 = 107 to 1100 C; n2D = 1.5422.

Example 3 344 g (1 mol) of octachlorocyclopentene are added dropwise at 45.degree within 2 hours 416 g (2 mol) of triisopropyl phosphite and holds by cooling the temperature of the reaction mixture to 45 "C. According to that described in the example Working up gives 240 to 260 g of isopropylpentachlorocyclopentadiene; Kp., 4 = 1260 C; n200 = 1.5400.

Example 4 34.4 g (0.1 mol) of octachlorocyclopentene are added with 69 g (0.21 mole) of tricyclohexyl phosphite heated to 80 "C for 8 hours. The mixture is then added worked up as in Example 1. Yield: 15 to 20 g of cyclohexylpentachlorocyclopentadiene; Bp 0.01 = 100 to 110 ° C.

Example 5 To 34.4 g (0.1 mol) octachlorocyclopentene, dissolved in 50 ccm of dry ether, 52 g of 2-oxabutyl- (4) -triphosphite are obtained at 350 C within 3 hours added dropwise.

The mixture is then kept at 350 ° C. for 4 hours and after evaporation of the ether worked up as indicated above. Yield 25 g of 2-oxabutyl- (4) -pentachlorocyclopentadiene; Bp 14 = 136 ° C; n200 = 1.5330.

Example 6 18.8 g of a-chloroethylheptachlorocyclopentene (mp.

112 "C), dissolved in a mixture of 50 ccm toluene and 100 ccm ether, 16.8 g of triethyl phosphite are added and the mixture is kept on the water stove while stirring heated until the ether is almost completely distilled off and the temperature of the reaction mixture has risen to 90 "C. After heating to 90" C for 5 hours, the residue is added with 200 ccm of water, then stir the mixture for a further 12 hours at room temperature, washes the mixture with water until it reacts neutral, dries and distilled she. There are in this way 10 to 12 g of a-Chloräthyläthyltetrachlorcyclopentadiene from bp 0.06 = 100 to 103 ° C and the refractive index n200 = 1.5428.

Claims (1)

Analysis: Calculated ... C = 36.6 <> f <>, °; 0, H = 3.101 ,, C1 = 60.2 ° 10; found ... C = 35.501 ,, H = 2.90 / ,, C1 = 61 00 / PATENT CLAIM: Process for the production of substituted cyclopentadienes, characterized in that that one mole of an optionally substituted polyhalocyclopentene, that too May be part of a polycyclic compound, having at least 3 halogen atoms at least 0.5 moles, but preferably with about 2 moles, of a tertiary phosphite -30 to + 150 ° C and the phosphoric acid diester halides formed during the reaction if desired subjected to solvolysis for better separation, in particular saponified or esterified.