반응 #2186223

반응 방정식

sodium hydroxide

5-amino-1 -(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl-1 H-pyrazole-3-carbonitrile

sulfuric acid

→

title compound

수율 77.0%

5-Amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-1H-pyrazole-3-carboxylic acid

수율 77.0%

반응 조건

후처리

1. 1
   추출extracted with ethyl acetate
2. 2
   건조The organic phase was dried over magnesium sulfate
3. 3
   기타evaporated to dryness
4. 4
   기타purified by flash chomatography (silica, chloroform/ethanol) with subsequently trituration with tetrachloromethane

실험 절차

A stirred mixture of 5-amino-1 -(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl-1 H-pyrazole-3-carbonitrile (5.00 g, 11.4 mmol) and sulfuric acid (50%, 100 ml) was heated to 135° C. for 3 hours. The cooled mixture was added to ice water and the pH adjusted to 4 by the addition of aqueous sodium hydroxide (6 N, approx. 230 ml), and then extracted with ethyl acetate. The organic phase was dried over magnesium sulfate, evaporated to dryness and purified by flash chomatography (silica, chloroform/ethanol) with subsequently trituration with tetrachloromethane to give the title compound (3.00 g, yield 77%) as off-white crystals, mp 213° C., 1H NMR (DMSO-d6): 5.69 (bs, 2H, NH2), 5.76 (s, 1H, pyrazole-H), and 8.20 (s, 2H, Ar—H).

출처