1-substituted 1,4,5,6-tetrahydropyridazines and 1-(N-substituted)-aminopyrrolidines from hydrazines and 2,5-dimethoxytetrahydrofuran

Article abstract of DOI:10.1016/S0040-4020(97)00142-7

N-Substituted 1,4,5,6-tetrahydropyridazines (3) can be prepared in a one pot procedure from a hydrazine 1 and 2,5-dimethoxytetrahydrofuran (2) using NaBH₄ in aqueous-THF acidic medium in fair yields, Variable amounts of two side products are also formed: hexahydropyridazines 5, likely produced by a route other than the direct reduction of 3, and 1-aminopyrrolidines 4. A direct reduction-N-reductive ethylation of3 could be achieved in AcOH with NaBH4_..