反应详情

Methyl 4-formylbenzoate (47 g, 285 mmol) was dissolved in methanol (400 ml) and a solution of 4-cyclohexylaniline (50 g, 0.285 mmol) in methanol (200 ml) is slowly added with mechanical stirring. More methanol (1 l) was added and the suspension was stirred at room temperature for 3 days. Filtration, washing and drying in vacuo afforded 90.7 g (99%) of 4-[(4-cyclohexylphenylimino)methyl]benzoic acid methyl ester. This was dissolved in N-methylpyrrolidone (855 ml) and methanol (45 ml). With mechanical stirring sodium borohydride pellets (42.4 g, 1.12 mol) was added in portions keeping the temperature below 40° C. The mixture was then stirred at room temperature for 2 hours and at 40° C. for 16 hours. The mixture was cooled to 5° C. and water (2 I) was slowly added. Then acetone (350 ml) was added and the mixture was stirred at 5° C. for 1 hour. Filtration, washing with water (2×500 ml) and drying in vacuo afforded 78 g (86%) of 4-[(4-cyclohexylphenylamino)-methyl]benzoic acid methyl ester as a solid.

1. filtrationFiltration
2. washwashing
3. customdrying in vacuo