反应详情

Quantities of 1.6 gm (10 mmol) of 4-hydroxy-1,2-phenylenediamine and 4.9 gm (20 mmol) of 2-methoxy-4-methanesulfonylamino-benzoic acid were refluxed for 1.5 hours, under stirring, in 80 ml of phosphorus oxychloride. The resulting dark solution was then decanted off to eliminate any undissolved components, the phosphorus oxychloride was distilled off in vacuo, and the residue was carefully mixed with 10 gm of crushed ice. Ten milliliters of 4N sodium hydroxide were added to the suspension thus obtained, and the resulting mixture was stirred for one hour at ambient temperature. It was then neutralized with concentrated hydrochloric acid, while being cooled, the solution was evaporated in vacuo to about 3 to 4 ml, the crude product precipitate was subjected to suction filtration, and the resultant crude product was purified by chromatography (250 gm of silica gel, eluant: methylene chloride with 5% ethanol).

1. customThe resulting dark solution was then decanted off
2. distillationthe phosphorus oxychloride was distilled off in vacuo
3. additionthe residue was carefully mixed with 10 gm of crushed ice
4. additionTen milliliters of 4N sodium hydroxide were added to the suspension
5. customthus obtained
6. temperaturewhile being cooled
7. customthe solution was evaporated in vacuo to about 3 to 4 ml
8. filtrationthe crude product precipitate was subjected to suction filtration
9. customthe resultant crude product was purified by chromatography (250 gm of silica gel, eluant: methylene chloride with 5% ethanol)