GB460647A - Improvements in insecticides - Google Patents

Abstract

Trichlormethyl - p - chlorphenyl carbinol is obtained by reacting chloral with chlorbenzol in presence of aluminium chloride, at low temperature. The reaction mixture is poured on ice and the oil layer washed, neutralized with soda, and fractionally distilled in vacuo. Trichlormethyl - p - bromphenol carbinol is similarly produced from chloral and benzol bromide. The solution is poured on ice and stirred with HCl and the oil layer neutralized and distilled. The acetates may be obtained by treating the carbinols with acetic anhydride and sodium acetate, neutralizing and recrystallizing with hot alcohol and active carbon. The monochloracetate, formate and methyl ester of trichlormethyl-p-chlorphenyl carbinol may also be prepared. The substances are used as insecticides. Other insecticidal substances referred to are acetonechloroform monochloracetate (from acetone and chloracetyl chloride), trichlormethyl - ethylmethyl carbinol (from methylethyl ketone and chloroform), trichlormethylisopropyl carbinol (from isobutylaldehyde and chloroform), and trichlormethylphenyl carbinol (from benzaldehyde and chloroform).ALSO:The active ingredients of insecticides consist of carbinols produced by reaction of chloral on chlorbenzol or brombenzol in presence of aluminium chloride as a catalyst, ethers or esters of these carbinols, acetone chloroform or its ethers or esters, or close homologues of these. The substances may be used as solutions or emulsions, or mixed with inert powders. Trichloromethyl - p - chlorophenyl carbinol is obtained by reacting chloral with chlorbenzol in presence of aluminium chloride at low temperature. After reaction, the solution is poured on ice and the oil layer washed, neutralized with soda and fractionally distilled in vacuo. The carbinol may be heated with acetic anhydride and sodium acetate, cooled, mixed with water to produce a precipitate of the acetate which is neutralized and recrystallized with hot alcohol and active carbon. The monochloracetate, formate and methyl ester may also be produced, also the corresponding trichloromethyl-p-bromphenol carbinol and its esters and ethers. Other active substances specified are acetonechloroformacetate, acetonechloroform monochloracetate (from acetone and chloracetylchloride), trichlorisopropanol, trichlormethyl-ethylmethyl carbinol (from methylethyl ketone and chloroform), trichlormethylisopropyl carbinol (from isobutyl aldehyde and chloroform), trichlormethylphenyl carbinol (from benzaldehyde and chloroform), and trichlormethylphenyl carbinol acetate.