反应详情

To a mixture of 4-hydroxybenzaldehyde (280.9 g), dimethyl malonate (289.2 mL) and toluene (1.12 mL) were successively added acetic acid (13.2 mL) and piperidine (11.4 mL). After dehydration under refluxing at internal temperature of 70° C.–75° C. for about 4 hr, the mixture was cooled to internal temperature of not more than 10° C. and stirred further for 1 hr. The precipitated crystals were collected by filtration and washed with toluene (350 mL) to give the title compound (compound [8]; 523.7 g, yield 96.4%).

1. temperatureAfter dehydration under refluxing at internal temperature of 70° C.–75° C. for about 4 hr
2. temperaturethe mixture was cooled to internal temperature of not more than 10° C.
3. filtrationThe precipitated crystals were collected by filtration
4. washwashed with toluene (350 mL)