The compounds of formula (I) are used as microbicides for treating plant diseases caused by Pythiaceae or Peronosporaceae. The compounds of formula (I) were already disclosed in Korean Patent Laid-open Publication No. 94-19960 and the corresponding foreign applications, for example, U.S. Pat. application Ser. No. 08/287,917, JP Patent Application No. 192529 and EP Patent Application No. 94112652.6 which were filed by the present applicant.
Further, a process for preparation of 2-aminothiazolecarboxamide derivatives including the compounds of formula (I) using 2-aminothiazole carboxylic acid as an intermediate was described in Korean Patent Laid-open Publication No. 97-24120. However, this process has the disadvantage that it is not economic when applied to industrial production due to the many steps for obtaining the intermediate and the low yield.
Accordingly, the present inventors have studied to improve the prior process by solving the above mentioned problems, and as a result, have brought the present invention to completion.