反应详情

Urea hydrogen peroxide addition compound (98% pure) (3.860 g, 40.9 mmol) was added to a stirring solution of 2,4-dichloro-6-methyl-nicotinic acid methyl ester (3.000 g, 13.6 mmol) in trifluoroacetic acid (15 ml) under nitrogen. The reaction mixture was stirred at room temperature for 18 hr. Additional urea-hydrogen peroxide addition compound (0.640 g, 6.8 mmol) was added and the reaction stirred for an additional 3 hr. Reaction mixture was poured over ice-water and stirred rapidly. The mixture was treated with sodium thiosulfate, adjusted to pH 11 with 2N aqueous NaOH and extracted 3 times with chloroform. The combined chloroform extracts were washed with water, brine, dried over sodium sulfate and concentrated to give 2.98 g (93%) of the title compound of Preparation C. 1H NMR (CDCl3) δ 7.26 (s,1H), 3.98(s,3H), 2.54(s,3H) ppm.

1. additionwas added
2. stirringthe reaction stirred for an additional 3 hr
3. customReaction mixture
4. stirringstirred rapidly
5. extractionextracted 3 times with chloroform
6. washThe combined chloroform extracts were washed with water, brine
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated
9. customto give