PREPARATION OF NITROPHENOL COMPOUND

摘要

PURPOSE:To provide the subject compound useful as a synthetic intermediate for medicines in a high purity and in a high yield under a mild condition by reacting a p-bromophenol compound with nitrous acid in mixed solvents comprising water and a water-insoluble or slightly soluble organic solvent. CONSTITUTION:A compound of formula I (R is 1-4C alkyl) is reacted with nitrous acid in mixed solvents comprising water and a water-insoluble or slightly soluble organic solvent (e.g., n-hexane or isopropyl ether) at 0-40 deg.C for 30min - 3hr to provide a compound of formula II. The mixed solvents have preferably a water:organic solvent volume ratio of 1:0.5-1. The nitrous acid is preferably produced in the above reaction system by adding a nitrous acid salt and an acid (e.g., sulfuric acid or trifluoroacetic acid) to the reaction system. The production of by-products are reduced in the above-mentioned method.