Pyridine → N-methyl-N-methoxy-(E)-5-methyl-4-bis(4-fluorophenyl)methylidene-2-hexenamide

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Reaction Conditions

Reaction Steps

To the above carboxylic acid (1.70 g, 5.2 mmol) dissolved in benzene (15 ml) was added under argon atmosphere oxalyl chloride (1.27 g, 0.87 ml, 10.0 mmol) distilled right before use. After stirring at 60° C. for 2 hours, the solvent and excess oxalyl chloride were removed by evaporation at 60° C. under 20 Torr. To the residue dissolved in dichloromethane (25 ml) were added N,O-dimethoxyhydroxylamine hydrochloride (0.52 g, 5.34 mmol) and pyridine (0.85 g, 0.86 ml, 10.7 mmol), and the whole was stirred at room temperature overnight. The mixture was diluted with diethyl ether (100 ml), and the organic layer was washed with saturated ammonium chloride aq solution (100 ml×twice), dried over anhydrous magnesium sulfate, and concentrated in vacuo. The resulting crude product was purified by column chromatography (silica gel, ethyl acetate:hexane=3:7) to give 1.62 g (82% yield) of N-methyl-N-methoxy-(E)-5-methyl-4-bis(4-fluorophenyl)methylidene-2-hexenamide.

Provenance & Evidence