NEW MATERIAL:A 4-methyl-5-(o-carboxyphenyl)carbamoylthiazole derivative shown by the formulaI(R1 is H or lower alkyl; R2 is lower alkyl, aryl, amino wherein phenyl group may be substituted, lower alkyl, phenyl, or pyridyl).

EXAMPLE: 2-Amino-4-methyl-5-( o-methoxycarbonylphenyl ) carbamoylthiazole.hydrobromide.

USE: Having antiphlogistic and analgestic action, antitumor action, useful as a drug.

PROCESS: For example, an o-α-halogen-substituted acetacetamido-benzoic acid shown by the formula II(X1 is H and X2 is Cl or Br, or X1 and X2 are Br) is reacted with a thioamide shown by the formula III, to give a compound shown by the formulaI. The compound shown by the formula II is also a novel compound, and, for example, synthesized by reacting an o-acetacetamidobenzoic acid with bromine in a solvent.