Hydrazine, dihydrochloride → Ethyl 3-oxo-6-(pyridin-2-yl)-2,3-dihydropyridazine-4-carboxylate

HRID 970190Notes

Reaction equation

HRID 970190 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]=1

Participants

4

Reactant 2

HCID 17548Hydrazine, dihydrochlorideHCID 59018088Ethyl 6-[4-(benzyloxy)phenyl]-3-oxo-2,3-dihydropyridazine-4-carboxylate

Product 1

HCID 20527880Ethyl 3-oxo-6-(pyridin-2-yl)-2,3-dihydropyridazine-4-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

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

  1. customafter purification by chromatography on silica gel (particle size 40-63 μm
  2. washunder an argon pressure of 150 kPa), eluting with dichloromethane
  3. customfollowed by recrystallization from ethanol

Sources & evidence

ORD record
ord-fd5ce3aefef0419a827b0cdce9293bfa
Source dataset
uspto-grants-2007_12
Patent number
US07309701B2

Reaction notes

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