Preparation of 2-amino-thiazole-5-carboxylic-acid derivatives

A method for preparing a compound of the structure I,

• wherein R is one or more residues selected from the group consisting of chlorine, methyl, ethyl, methoxy and ethoxy, which comprises providing a compound of the structure II
• and reacting the above compound with substituted anilines of the structure III,
• wherein R has the same meaning as above, in the presence of an inorganic base and subjecting the reaction mixture to a reaction with an alkanolate salt to give a compound of formula IV,
• which compound is reacted with thiourea in an acidic medium to give the compound of formula I.