Studies on Heterocyclic Compounds. XVIII. Synthesis of Furo [2, 3-d] pyridazine Derivatives. (6). Nitration of 4-Oxo-7-chloro-4, 5-dihydrofuro [2, 3-d] pyridazine

Abstract

Nitration of 4-oxo-7-chloro-4, 5-dihydrofuro [2, 3-d] pyridazine (V) with 96% sulfuric acid and fuming nitric acid gave 2-nitro-4-oxo-7-chloro-4, 5-dihydrofuro [2, 3-d] pyridazine (VII) and trans-2-nitro-3-hydroxy-4-oxo-7-chloro-2, 3, 4, 5-tetrahydrofuro [2, 3-d]-pyridazine (VIII). Nitration of V with 75% sulfuric acid and fuming nitric acid gave three products ; VII, VIII and cis-2-nitro-3-hydroxy-4-oxo-7-chloro-2, 3, 4, 5-tetrahydrofuro [2, 3-d] pyridazine (IX). The structure assignment of this trans-cis isomers were described.