Sodium hydride → HCID 10291825, compound

Reaction equation

Br[CH2:2][C:3]([O:5][CH3:6])=[O:4].[H-].[Na+].[Cl:9][C:10]1[CH:11]=[C:12]([CH:23]=[C:24]([Cl:26])[CH:25]=1)[O:13][C:14]1[C:15]([CH2:21][CH3:22])=[N:16][NH:17][C:18]=1[CH2:19][CH3:20]>CN(C=O)C>[Cl:9][C:10]1[CH:11]=[C:12]([CH:23]=[C:24]([Cl:26])[CH:25]=1)[O:13][C:14]1[C:18]([CH2:19][CH3:20])=[N:17][N:16]([CH2:2][C:3]([O:5][CH3:6])=[O:4])[C:15]=1[CH2:21][CH3:22]

Participants

Procedure

Methyl bromoacetate (984 μL, 10 mmol) and then sodium hydride (60% dispersion in oil, 801 mg, 20.1 mmol) were added to a stirred solution of the pyrazole (2.6 g, 9.12 mmol) of Example 3 in dry N,N′-dimethylformamide (25 ml) at 0° C. under nitrogen. After stirring for 1 hour at 0° C. ice-water (100 ml) was added and the mixture was extracted with ether (3×50 ml). The combined ether layers were dried over magnesium sulphate, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel eluting with ethyl acetate:pentane (20:80, by volume) to provide the title compound (780 mg) as a yellow oil which partly crystallised on standing.