Novel polyfunctional derivatives of 2-methylbutanoic acid and novel process for the preparation of these and other 2-methylbutanoic acid derivatives

摘要

2,4-Disubstituted and 2,3,4-trisubstituted 2-methylbutanoic acid derivatives of the general formula (I) IMAGE in which R1 stands for a straight or branched alkyl group having 1-9 carbon atoms, for a cycloalkyl group which has 5-7 carbon atoms in the ring and is optionally mono- or disubstituted by alkyl having 1-4 carbon atoms, or for a phenylalkyl group having 1-3 carbon atoms in the alkyl moiety, which can be substituted in the ring by alkyl and/or alkoxy each having 1 or 2 carbon atoms, R2 denotes hydrogen, a straight or branched alkyl group having 1-4 carbon atoms, an aryl group optionally substituted by alkyl or alkoxy having 1 or 2 carbon atoms, an alkanoyl group having 1-4 carbon atoms or a group IMAGE in which the meaning of R1 is the same as above, and R3 stands for an alkanoyl group having 1-4 carbon atoms, for an aryl group which is optionally substituted by alkyl or alkoxy having 1 or 2 carbon atoms, for a cyano group or a group IMAGE in which the meaning of R1 is the same as above with the restriction that if R3 = CN R2 has a meaning other than hydrogen, and a process for their preparation.v