反応 #2286377

反応方程式

Water

HCl

2-pyridin-3-yl-4-trifluoromethyl-thiazole-5-carboxylic acid ethyl ester

sodium hydroxide

→

desired product

収率 58.4%

2-pyridin-3-yl-4-trifluoromethyl-thiazole-5-carboxylic acid

収率 58.4%

溶媒

methanol

反応条件

後処理

1. 1
   その他a precipitate was formed
2. 2
   ろ過the heterogeneous mixture was filtered under reduced pressure
3. 3
   洗浄The precipitate was rinsed further with water
4. 4
   その他dried in vacuo

実験手順

To a solution of 2-pyridin-3-yl-4-trifluoromethyl-thiazole-5-carboxylic acid ethyl ester (13.9 g, 46 mmol, ca. 85% pure) in methanol (150 mL) was added an aqueous solution of sodium hydroxide (total volume 75 mL, 140 mmol), and the mixture was stirred for 40 min. Upon addition of 2 N HCl (70 mL, ca pH=3) to the reaction mixture, a precipitate was formed. Water (300 mL) was then added and the heterogeneous mixture was filtered under reduced pressure. The precipitate was rinsed further with water and dried in vacuo to give the desired product as an off-white solid (7.37 g, 58%): mp 209° C.; 1H NMR (300 MHz, DMSO-d6) δ 9.21 (d, J=2.5 Hz, 1H), 8.77 (dd, J=4.9, 1.7 Hz, 1H), 8.41 (dt, J=8.0, 1.7 Hz, 1H), 7.60 (dd, J=8.0, 4.9 Hz, 1H), 3.4 (br s, 1H); ESIMS m/z 276.2 (M+1).

出典