Sodium hydride → t-Butyl methyl 7-bromoheptylmalonate

Reaction equation

[H-].[Na+].[C:3]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])(=[O:9])[CH2:4][C:5]([O:7][CH3:8])=[O:6].[Br:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22]Br>CN(C)C=O>[Br:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH:4]([C:5]([O:7][CH3:8])=[O:6])[C:3]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9]

Participants

Procedure

Sodium hydride (3.04 g of a 50% oil dispersion, 127 mmol) is suspended in dimethylformamide (300 ml) and the suspension is cooled to 0° C. t-Butyl methyl malonate (20.08 g, 115 mmol) is added dropwise slowly and the reaction mixture is warmed to room temperature. 1,7-Dibromoheptane (29.75 g, 115 mmol) is added dropwise and the mixture is stirred for 3 hours. The mixture is partitioned between diethyl ether (500 ml) and water (1000 ml). The organic layer is washed with water (3×500 ml), brine (1×500 ml), dried (MgSO4) and the solvent is evaporated. The product is purified by silica gel chromatography (10% ethyl acetate/hexane) to give t-butyl methyl 7-bromoheptylmalonate as an oil.