(METHOD FOR PREPARATION 3-CARBOXY-4-HYDROXYBENZALDEHYDES AND DERIVATIVES THEREOF) FOR PRODUCING 3-CARBOXY-4-HYDROXYBENZALDEHYDES AND DERIVATIVES THEREOF

摘要

The present invention relates to a process for the preparation of 3-carboxy-4-hydroxybenzaldehyde and its derivatives from phenolic compounds carrying formyl and / or hydroxymethyl groups at the 2 and 4 positions.;The present invention also relates to the preparation of 4-hydroxybenzylaldehyde from 3-carboxy-4-hydroxybenzaldehyde.;More particularly, the present invention relates to the preparation of 3-methoxy-4-hydroxybenzaldehyde and 3-ethoxy-4-hydroxybenzaldehyde, respectively known as vanillin and ethyl vanillin.;The process for producing 3-carboxy-4-hydroxybenzaldehyde is characterized in that the 2-position group of the phenolic compound carrying formyl and / or hydroxymethyl group at positions 2 and 4 is selectively oxidized to a carboxy group, Characterized in that the RTI ID = 0.0 Roxymethyl /RTI ;The subsequent decarboxylation step of 3-carboxy-4-hydroxybenzaldehyde yields 4-hydroxybenzaldehyde.