反应详情

A mixture of 5,7-diamino-1,3-dimethylpyrimido-(4,5-c)pyridazin-4(1H)-one (0.50 g) and 1.5 N aqueous sodium hydroxide (35 ml) was stirred at reflux for 24 hours after which time a small amount of solid was removed by filtration of the hot mixture. On cooling, the yellow filtrate deposited white needles which were collected by filtration and dissolved in warm water (20 ml). Adjustment of this aqueous solution to pH 5 by dropwise addition of 6 N hydrochloric acid and subsequent cooling to room temperature provided a very finely divided white precipitate which was collected, washed with water and dried under vacuum at 70° C. to give 7-amino-1,3-dimethylpyrimido-(4,5-c)pyridazine-4,5(1H, 6H)-dione (0.38 g; 76% of theoretical yield). The u.v., i.r., and n.m.r. spectra of this compound were identical to those of the sample made according to the procedure of Example 2.

1. temperatureat reflux for 24 hours after which time a small amount of solid
2. customwas removed by filtration of the hot mixture
3. temperatureOn cooling
4. filtrationwere collected by filtration
5. dissolutiondissolved in warm water (20 ml)
6. additionAdjustment of this aqueous solution to pH 5 by dropwise addition of 6 N hydrochloric acid
7. customprovided a very finely divided white precipitate which
8. customwas collected
9. washwashed with water
10. customdried under vacuum at 70° C.