A relatively cheap 4-hydroxy-3-nitrobenzoic acid was hydrogenated to yield 3-amino-4-hydroxy-ben-zoic acid,then the amino acid was condensed with met-hyl chloroformate (or ethyl chloroformate) to afford benzo [d]oxazoline-2-one-5-carboxylic acid, the structure of the title product was identified by 1H NMR and MS. The overall yield of the new method was 81.6%. The method is better with a simple process, mild conditions, high yield,and facilitate industrial synthesis.%利用较价廉的3-硝基4-羟基苯甲酸在Pd/C催化下氢化还原得3-氨基-4-羟基苯甲酸,再与氯甲酸甲酯(或氯甲酸乙酯)成环得苯并[d]噁唑啉-2-酮-5-羧酸.目标化合物经1H NMR和MS确证,总收率为81.6％.该方法工艺简单,条件温和,收率较高,便于工业合成.
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