反应详情

1-Hydroxybenzotriazole (273 mg, 2.0 mmol), 2-phenylethylamine (0.125 ml, 1.0 mmol) and N-methylmorpholine (0.222 ml, 2.0 mmol) were added to a solution of (4-dimethylamino-4-phenylcyclohexyl)acetic acid hydrochloride (298 mg, 1.0 mmol) in dry dimethylformamide under argon. Dicyclohexylcarbodiimide (417 mg, 2.0 mmol) was added at 0° C. and the mixture was stirred at RT for 5 d. The urea which had precipitated out was filtered off with suction and the filtrate was introduced into a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml). Still further urea thereby precipitated out as a mixture with the product (349 mg) and was separated off. The filtrate obtained was diluted with water (300 ml), 5 M sodium hydroxide solution (8 ml, 40 mmol) was added and the mixture was stored at 5° C. for 16 h. Further product thereby precipitated out as a colourless solid (172 mg). After purification of the fraction contaminated with dicyclohexylurea by chromatography on silica gel with methanol, further product (49 mg) was obtained. The product was isolated in a total yield of 61% (221 mg) with an m.p. of 182-186° C.

1. customThe urea which had precipitated out
2. filtrationwas filtered off with suction
3. additionthe filtrate was introduced into a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml)
4. customStill further urea thereby precipitated out as a mixture with the product (349 mg)
5. customwas separated off
6. customThe filtrate obtained
7. additionwas added
8. waitthe mixture was stored at 5° C. for 16 h
9. customFurther product thereby precipitated out as a colourless solid (172 mg)
10. customAfter purification of the fraction