反应详情

A suspension of 15.3 g (0.058 mol) 2-(phenylsulfonyl)-ethanimidic acid ethyl ester hydrochloride in 125 ml chloroform was treated with 58.1 ml 1N aqueous sodium hydoxide. 18 ml of a saturated aqueous sodiumbicarbonate solution was added and the mixture was extracted with chloroform. The extracts were combined and dried with sodium sulfate and the solvents were distilled off under reduced pressure. The resulting colorless oil was stirred together with 10.0 g (0.058 mol) 2,4-difluorobenzoic acid hydrazide in 110 ml chloroform over night at 50° C. The resulting precipitate was filtered off and dried. A yield of 8.50 g (42%) 2,4-difluoro-benzoic acid (1-amino-2-benzenesulfonyl-ethylidene)-hydrazide was obtained as white solid. MS m/e (%): 354 (M+H+, 100).

1. extractionthe mixture was extracted with chloroform
2. dry with materialdried with sodium sulfate
3. distillationthe solvents were distilled off under reduced pressure
4. filtrationThe resulting precipitate was filtered off
5. customdried