反应详情

温度

0 °C

To a stirred suspension of 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-methylsulfinyl-1H-pyrazole-3-carbonitrile (5.0 g) in anhydrous methanol was added a 25% w/w solution of sodium methoxide (8.95 ml) in methanol, at 20° C. The mixture was stirred for 16-hours, cooled to 0° C. and diluted with ice-cold anhydrous methanol. Carbon dioxide was passed into the solution for 15-minutes until a pH of 8 was attained. The precipitate was filtered off, washed (ethyl acetate) and evaporated to give 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-methylsulfinyl-1H-pyrazole-3-carboximidic acid methyl ester (3.65 g), 1H NMR (CDCl3) in ppm: 8.34(s,1H), 7.79(s,2H), 5.11(brs,2H), 3.93(s,3H), 2.94(s,3H). By proceeding in a similar manner the following compound was prepared: 5-Amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-trifluoromethylsulfinyl-1H-pyrazole-3-carboximidic acid methyl ester, m.p.179-180° C.

1. customat 20° C
2. additiondiluted with ice-cold anhydrous methanol
3. filtrationThe precipitate was filtered off
4. washwashed (ethyl acetate)
5. customevaporated