1975 Volume 23 Issue 10 Pages 2239-2250
Investigations on the preparative methods and some chemical modifications of the previously reported potent diuretic, 1, 4-dimorpholino-7-phenylpyrido [3, 4-d] pyridazine (1 : DS-511) were undertaken, producing a variety of derivatives shown in Table I. Comparison of the reactivity between the two chloro groups in 1, 4-dichloropyrido [3, 4-d] pyridazine showed that the 4-chloro group is more reactive toward nucleophilic substitution than the 1-chloro group. Some reaction of 1, e. g. acid hydrolysis, reduction and Grignard addition reaction were also carried out. Significance of the ring nitrogen at the 6-position in 1 for diuretic activity is discussed.
