反应详情

128 mg (1.14 mmol) of 5-hydroxy-1,3-dimethylpyrazole were added to 270 mg (purity 95% by weight; 1.04 mmol) of 4-chloro-3-ethylsulfinyl-2-methylbenzoic acid in 20 ml of dichloromethane (CH2Cl2). 239 mg (1.24 mmol) of 1-(3′-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added, and the mixture was stirred at RT for 16 h. For work-up, 3 ml of 1M HCl were added, and the organic phase was freed from the solvent. 210 mg (2.07 mmol) of triethylamine, 10 drops of acetone cyanohydrin and a spatula tip of potassium cyanide were added to the residue in 20 ml of acetonitrile. The reaction mixture was stirred at RT for 16 h and then freed from the solvent. The residue was stirred at RT with 25 ml of a mixture of aqueous saturated sodium bicarbonate solution and diethyl ether for 10 min. The phases were separated, and the aqueous phase was acidified with dilute HCl and then extracted with CH2Cl2. The organic phase was freed from the solvent and the residue was then purified chromatographically. This gave 100 mg of clean product.

1. stirringThe reaction mixture was stirred at RT for 16 h
2. customThe phases were separated
3. extractionextracted with CH2Cl2
4. customthe residue was then purified chromatographically