Heterocyclic Imines And Amines .14. Products From 2,5-Diiminopyrrolidine (Succinimidine) And Hydrazine

Hydrazine (in excess) reacts with 2,5-di-iminopyrrolidine (1) or succinonitrile to yield 6-hydrazino-3-hydrazono-2,3,4,5-tetrahydropyridazine (2). Treatment of this with acetone, glyoxylic acid, and butyl glyoxylate affords the expected di-condensation products; with glyoxal a polymeric hydrazone is obtained. Acylation of compound (2) with ethyl chloroformate was successful but attempts to oxidise the product to known pyridazines failed, as did attempts to dehydrogenate compound (2) to 3,6-dihydrazinopyridazine. 5-lmino-2-pyrrolidone (13) with hydrazine gave 6-hydrazino-4.5-dihydropyridazin-3(2H)-one (14).