PURPOSE: A new compound useful as a raw material for excellent compatibilizing agents changing different kinds of non-compatible polymers into a homogeneous molecular mixture.

CONSTITUTION: A compound of the formula (R1 is H, 1-12C alkyl; R2, R3 are H, 1-4C alkyl), e.g. 2-isopropenylbenz[d]oxazolone. The compound of the formula is easily obtained by dehydration-condensing an amidocarboxylic acid obtained by reacting an anthranilic acid derivative with an α,β-unsaturated carboxylic acid chloride. A compatibilizing agent can be produced by grafting the compound of the formula to a specific polymer or by copolymerizing the compound of the formula with plural monomers.