Hydrazine, dihydrochloride → Ethyl 3-oxo-6-(pyridin-2-yl)-2,3-dihydropyridazine-4-carboxylate
Reaction equation
C(O[C:9]1[CH:14]=C[C:12]([C:15]2[CH:16]=[C:17]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[C:18](=[O:21])[NH:19][N:20]=2)=[CH:11][CH:10]=1)C1C=CC=CC=1.Cl.Cl.[NH2:29]N>C(O)C>[N:29]1[CH:14]=[CH:9][CH:10]=[CH:11][C:12]=1[C:15]1[CH:16]=[C:17]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[C:18](=[O:21])[NH:19][N:20]=1Participants
4
Procedure
Working as in example 19 for the preparation of ethyl 6-[4-(benzyloxy)phenyl]-3-oxo-2,3-dihydropyridazine-4-carboxylate, but starting with 31.1 g of diethyl hydroxy(pyridin-2-oxoethyl)malonate, 11.55 g of hydrazine dihydrochloride and 700 cm3 of ethanol, and after purification by chromatography on silica gel (particle size 40-63 μm, under an argon pressure of 150 kPa), eluting with dichloromethane, followed by recrystallization from ethanol, 6.9 g of ethyl 6-pyridin-2-yl-3-oxo-2,3-dihydropyridazine-4-carboxylate were obtained in the form of a yellow solid melting at 182° C.
Workup
- customafter purification by chromatography on silica gel (particle size 40-63 μm
- washunder an argon pressure of 150 kPa), eluting with dichloromethane
- customfollowed by recrystallization from ethanol
Sources & evidence
- ORD record
- ord-f2beb9c1320f46548da95d537a55c7a3
- Source dataset
- uspto-grants-2008_12
- Patent number
- US07462613B2
Reaction notes
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