Process for preparing 3-nitro-4-alkoxybenzoic acid

摘要

The present invention provides a process for preparing 3-nitro-4-alkoxybenzoic acid, which comprises the step of subjecting a mixture comprising 4-alkoxybenzoic acid and 40-80% nitric acid, wherein the amount of the 40-80% nitric acid is equal to or more than 8 times that of 4-alkoxybenzoic acid by weight, to a reaction at a temperature of 30-100° C.