反应详情

An amount of 1.05 gm of 2-(2-methoxy-4-amino-phenyl)-5H-imidazo[4,5-d]pyridazin-4-one is suspended in 20 ml of 6N hydrochloric acid. The suspension is cooled to 0° to -3° C., and 0.28 gm of sodium nitrite, dissolved in 2 ml of water, are added dropwise thereto. The mixture is stirred for a further 40 minutes and then heated to 80°-85° C. for one hour. The product precipitated on cooling is purified by chromatography on silica gel [eluant: first methylene chloride/ethanol (100:0 to 100:20, then 1.5 to 2.5% of glacial acetic aicd is added)].

1. temperatureThe suspension is cooled to 0° to -3° C.
2. additionare added dropwise
3. temperatureheated to 80°-85° C. for one hour
4. customThe product precipitated
5. temperatureon cooling
6. customis purified by chromatography on silica gel [eluant
7. additionfirst methylene chloride/ethanol (100:0 to 100:20, then 1.5 to 2.5% of glacial acetic aicd is added)]