摘要 |
<p>An improved process for producing a catechol derivative (1) useful as a intermediate of pharmaceuticals and agricultural chemicals, being shown by the following reaction scheme. The process is characterized in that formulation in the first step is carried out in the two stages, that is, the reaction is carried out in the presence of a tin catalyst at 60-85 DEG C to a conversion of 30 to 80% and then is completed at 95-105 DEG C to produce a salicylaldehyde derivative (3) in a high yield and a high selectivity. Thereby, the objective catechol derivative (1) can be obtained in a high yield and with a high purity. <CHEM> In the above formula, R is alkyl, cycloalkyl, aralkyl, alkoxy, halogen atom , allyl, or aryl, and R<1> is a hydroxy protective group.</p> |