反应详情

温度

0 °C

(4-dimethylamino-4-phenylcyclohexylidene)acetic acid hydrochloride (592 mg, 2.0 mmol) in dry dimethylformamide (10 ml) under argon. The clear solution was cooled to 0° C. and dicyclohexylcarbodiimide (834 mg, 4.0 mmol) was added. The reaction mixture was stirred at RT for 4 d. Working up of the mixture was carried out by separating off the urea which had precipitated out and introducing the filtrate into a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml). Still further urea thereby precipitated out and was separated off. 5 M sodium hydroxide solution (5 ml, 25 mmol) was added to the aqueous phase and the mixture was diluted with water (300 ml) and stored at 5° C. for 16 h. The product thereby precipitated out as a colourless solid in a yield of 45% (387 mg) with an m.p. of 77-88° C.

1. customby separating off the urea which
2. customhad precipitated out
3. additionintroducing the filtrate
4. additioninto a mixture of saturated NaCl solution (40 ml) and saturated NaHCO3 solution (10 ml)
5. customStill further urea thereby precipitated out and
6. customwas separated off
7. waitstored at 5° C. for 16 h
8. customThe product thereby precipitated out as a colourless solid in a yield of 45% (387 mg) with an m.p. of 77-88° C.