NEW MATERIAL: A compound of formula I (A is 5-6-membered unsubstituted or substituted aromatic heterocyclyl with the exception of pyrrolyl, 5-6-membered aromatic heterocyclyl-vinyl, unsubstituted or substituted phenyl; B is unsubstituted or substituted phenyl, pyridyl, thazolyl, with the proviso that when A is unsubstituted phenyl, B does not represent unsubstituted phenyl, methylphenyl or methoxphenyl) or an enol tautomer, lower alkyl enol ether or salt therof.

EXAMPLE: p-chloro-α-cyano-β-oxo-β-(2-thienyl)propionamide.

USE: An antiinflammatory agent, an analgesic and an antirheumatic agent.

PREPARATION: A compound of formula II, etc., and a compound of formula III; a compound of formula IV, etc., and a compound of the formula B-NH2; or a compound of the formula A-COOH, etc., and a compound of formula V, etc., are condensed, respectively, to obtain a compound of formula I.