ES352579A1 - A procedure for the preparation of an oxazolol replaced by monoaryl. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Novel compounds I and their acid addition salts in which R1 is phenyl, halophenyl, alkylphenyl, alkoxyphenyl, nitrophenyl, haloalkylphenyl, mercaptophenyl, alkylthiophenyl, aminophenyl, dialkylaminophenyl, alkylsulphonylphenyl, naphthyl or heteroaryl R2 is H, 1-4 C alkyl, aryl or heteroaryl and R3 is a 2-6 C aliphatic carboxylic acid radical attached via a C of its aliphatic chain or an ester, amide, salt or hydroxamic acid derivative of the COOH group in said radical R3 with the provisos (a) that when R1 is phenyl optionally substituted by CF 3 or up to 2 halo and when R2 is 5-H, then R3 has at least 2 C in a straight chain between the oxazole ring and the COOH group or its derivative and (b) that if R1 is phenyl and R3 is a 4-acrylic or n-propionic acid radical R2 is not H are prepared by (a) when R3 and R2 are in the 4- and 5-positions respectively, reacting (where R4 is as R3 or is convertible thereto) with R1CONH 2 (b) when R3 and R2 are in the 5- and 4-positions respectively, reacting alkyl -OOC-CH(hal)COR2 in the form of an enamine with ammonia or an amine and an aroyl peroxide to give compounds V which are then cyclized (c) when R3 and R2 are positioned as in (b), reacting alkyl OOC-CH(M)COR2 (M is an alkali metal) with an aroyl peroxide to give compounds VI which are then cyclized in the presence of a N-donating agent to give I (d) hydrolysis of esters to give acids (e) hydrolysis of nitriles to amides and acids or (f) esterification of the acids. Intermediates isolated are 4-chloromethyl-2- phenyl-oxazole, prepared from benzamide and sym-dichloroacetone and 4-cyanomethyl-2- phenyl-oxazole, prepared from the former intermediate and NaCN.