Hydrazine hydrate (1:1) → [6-chloro-5-(3,6-dihydro-2H-pyridin-1-yl)-pyridazin-3-yl]hydrazine
Reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][C:7]=1[N:8]1[CH2:13][CH:12]=[CH:11][CH2:10][CH2:9]1.O.[NH2:16][NH2:17]>O1CCOCC1>[Cl:1][C:2]1[N:3]=[N:4][C:5]([NH:16][NH2:17])=[CH:6][C:7]=1[N:8]1[CH2:13][CH:12]=[CH:11][CH2:10][CH2:9]1Participants
4
Procedure
A mixture of 3,6-dichloro-4-(3,6-dihydro-2H-pyridin-1-yl)pyridazine (1.7 g, 7.4 mmol) and hydrazine hydrate (2.2 ml) in dioxan was stirred and heated at reflux under nitrogen for 24 hours. Upon cooling the dioxan was removed in vacuo and the residue was partitioned between dichloromethane and water. The aqueous was further extracted with dichloromethane (×3). The combined extracts were dried (MgSO4), filtered and evaporated. The residue was triturated with ether/MeOH and dried in vacuo to afford the title pyridazine (1.5 g, 88%). 1H NMR (250 MHz, d6-DMSO) 7.8 (1H, br s), 6.48 (1H, s), 5.76 (2H, m), 4.21 (2H, br s), 3.51 (2H, m), 3.24 (2H, m), 2.16 (2H, m). MS (ES+) 226 [MH]+, 228 [MH]+.