| 摘要 |
<p>An improved process for producing catechol derivatives (1) useful as intermediates for compounds useful as drugs or agricultural chemicals, which comprises the reaction steps shown above. In said process (I), R represents alkyl, cycloalkyl, aralkyl, alkoxy, halogeno, allyl or aryl, and R1 represents a hydroxy-protecting group. The process is characterized in that formylation as the first step is conducted in the presence of a tin catalyst in two stages, first at 60 to 85 °C to a conversion of 30 to 80 % and then at 95 to 105 °C to completion, to thereby obtain a salicylaldehyde (3) in a high yield with a high selectivity. The objective catechol derivatives (1) having a high purity are hence obtained in a high yield.</p> |
