| 摘要 |
PURPOSE:To industrially and advantageously obtain the subject compound useful as an intermediate for medicines and agricultural chemicals from a compound producible inexpensively in a large amount, for example, by reacting a 1,4- dialkoxy-2-butanone with an acetoacetic ester in the presence of a base. CONSTITUTION:A compound shown by formula II (R1 and R2 are 1-4C alkyl) producible inexpensively in a large amount is reacted with a compound shown by the formula R3SH (R3 is 1-4C alkyl) in the presence of an acid catalyst to give a compound shown by formula IV (e.g. methyl 3-methoxy-2-methyl-4- methylthio-1,3cyclohexanedienecarboxylate). Further, the compound shown by formula IV compound is dehydrogenated to give a compound shown by formula III, which is then oxidized to give a compound shown by formula V ((n) is 0-2). Finally this compound is hydrolyzed to give the objective compound shown by formula I (e.g. 3-methoxy-2-methyl-4-methylsulfonylbenzoic acid). |
