反应详情

50 g (0.23 mol) of methyl 2-methyl-6-trifluoromethylnicotinate and 49 g (0.28 mol) of N-bromosuccinimide are heated for 90 minutes at 50° C. in 500 ml of carbon tetrachloride in the presence of a catalytic amount of α,α-azaisobutyronitrile with illumination by a 150 watt lamp. Precipitated succinimide is filtered off, and the product methyl 2-bromomethyl-6-trifluoromethylnicotinate is then isolated as main component by means of column chromatography (mobile phase ethyl acetate/hexane 1:15), 1H-NMR (CDCl3): 4.01, s, 3H; 5.03, s, 2H; 7.72, d (J 8.2 Hz), 1H; 8.43 ppm, d, (J 8.2 Hz), 1H. 25.6 g (35 mmol) of the above product are taken up in toluene and treated with 10.6 g (40 mmol) of triphenylphosphine. After the mixture has been heated for 2 hours at boiling point, pure (3-methoxycarbonyl-6-trifluoromethylpyridine-2-ylmethyl)triphenylphosphonium bromide of melting point 215-217° C. crystallizes out upon cooling.

1. filtrationPrecipitated succinimide is filtered off