GB746015A - Acylamino phenone compounds and method for preparing same - Google Patents

Abstract

The invention comprises a -acylamino-b -hydroxy - 4 - mercaptopropiophenone compounds of the general formula <FORM:0746015/IV(a)/1> (wherein R represents a hydrocarbon radical of 1-7 carbon atoms and Y an aliphatic carboxylic acylamino radical), and the preparation thereof by hydroxymethylation (e.g. with formaldehyde in the presence of a small amount of sodium bicarbonate) of compounds of the general formula <FORM:0746015/IV(a)/2> The reaction may be carried out at 0-70 DEG C., preferably 20-50 DEG C., using formaldehyde in the form of a gas, an aqueous or alcoholic solution or paraformaldehyde. The substituents R and Y may be any of those enumerated in Specification 745,900, compounds in which R is alkyl and Y is haloalkanoylamino being preferred. In examples the following compounds are hydroxymethylated by warming a solution or suspension thereof in ethanol with aqueous formaldehyde and sodium bicarbonate: (1) a acetylamino - 4 - methylmercaptoacetophenone; (2) a - dichloracetylamino - 4 - methylmercaptoacetophenone; (3) a - dichloroacetylamino - 4 - ethylmercaptoacetophenone; (4) a dichloroacetylamino - 4 - n - propylmercaptoacetophenone; (5) a - dichloroacetylamino - 4-n - butylmercaptoacetophenone; (6) a - acetylamino - 4 - benzylmercaptoacetophenone; (7) a - dichloroacetylamino - 4 - benzylmercaptoacetophenone; (8) a - dichloroacetylamino - 4-phenylmercaptoacetophenone. Additional starting materials specified are: a -iodoacetylamino4 - p - tolymercaptoacetophenone, a - (b chloropropionylamino) - 4 - cyclohexylmercaptoacetophenone, a - acetylamino - 4 - methallylmercaptoacetophenone and a - (a :b - dichloropropionylamino - 4 - tert. - butylmercaptoacetophenone. a - Acylamino - 4 - hydrocarbonylmercaptoacetophenones of the second general formula above are prepared by the action of an acylating agent (e.g. an acyl halide or anhydride, advantageously in an anhydrous organic solvent or in an alkaline aqueous solution) on the corresponding amines, which in turn are obtained by reacting the appropriate thiophenol ether with acetyl chloride in the presence of aluminium chloride, brominating the resulting 4-hydrocarbonylmercaptoacetophenone in the a -position, and replacing the bromine atom by NH2, e.g. by condensation with hexamethylene tetramine followed by hydrolysis with aqueous alcoholic hydrochloric acid. The preparation of the starting materials for the examples above is described in detail.