Ethylacetate methanol → Methyl 1-(4-bromo-2,5-difluorophenyl)-5-methoxy-4-oxo-1,4-dihydropyridazine-3-carboxylate

HRID 1624693Notes

Reaction equation

HRID 1624693 reaction equation
[Br:1][C:2]1[C:7]([F:8])=[CH:6][C:5]([NH:9][N:10]=[C:11]([C:16](=[O:20])[CH2:17][O:18][CH3:19])[C:12]([O:14][CH3:15])=[O:13])=[C:4]([F:21])[CH:3]=1.[CH3:22]COC(C)=O.CO>COC(OC)N(C)C>[Br:1][C:2]1[C:7]([F:8])=[CH:6][C:5]([N:9]2[CH:22]=[C:17]([O:18][CH3:19])[C:16](=[O:20])[C:11]([C:12]([O:14][CH3:15])=[O:13])=[N:10]2)=[C:4]([F:21])[CH:3]=1

Participants

4

Reactant 2

HCID 21584119Ethylacetate methanolHCID 178496284methyl 2-[(4-bromo-2,5-difluorophenyl)hydrazinylidene]-4-methoxy-3-oxobutanoate

Product 1

HCID 58072213Methyl 1-(4-bromo-2,5-difluorophenyl)-5-methoxy-4-oxo-1,4-dihydropyridazine-3-carboxylateYield 83%

Reagents, catalysts & solvents 1

HCID 78373Dimethylformamide dimethyl acetalSolvent

Procedure

A solution of methyl 2-[(4-bromo-2,5-difluorophenyl)hydrazono]-4-methoxy-3-oxobutanoate (33 g, 90 mmol) in N,N-dimethylformamide dimethyl acetal (72 mL) was stirred at 110° C. for 3 h. After cooling to room temperature, the mixture was concentrated under reduce pressure. To the residue were added MeOH and silica gel The mixture was evaporated and purified by silica gel column chromatography eluting with hexane/AcOEt (1/0 to 0/1) and then AcOEt/MeOH (4/1) to give the title compound (27.9 g, 83% yield) as a brown gum: 1H NMR (300 MHz, DMSO-d5): δ ppm 3.80 (3H, s), 3.83 (3H, s), 8.01 (1H, dd, J=8.7, 6.8 Hz), 8.15 (1H, dd, J=9.8, 6.0 Hz), 8.55 (1H, d, J=1.5 Hz). LC-MS (ESI) m/z 376 [M+H]+.

Workup

  1. concentrationthe mixture was concentrated
  2. additionTo the residue were added MeOH and silica gel The mixture
  3. customwas evaporated
  4. custompurified by silica gel column chromatography
  5. washeluting with hexane/AcOEt (1/0 to 0/1)

Sources & evidence

ORD record
ord-8fdc7721c46844c3a08ae79b4a2d6d8d
Source dataset
uspto-grants-2014_07
Patent number
US08778944B2

Reaction notes

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