反应详情

4-n-butylbenzoic acid (8, 50 g, 0.28 mol) was dissolved in glacial acetic acid (250 ml ) and the solution was then autoclaved and hydrogented over platinum oxide (2.0 g) at 20° C. for 18 hr. at 5- p.s.i. The catalyst was filtered and the solution evaporated in vacuo to leave a solid residue of predominantly cis-4- n-butylcyclohexanecarboxylic acid (9, 50.89). The solid was dissolved in dry dichloromethane (250ml) containing N,N-dimethylformamide (1 ml). Thionyl chloride (72.69, 0.61 mol) was cautiously added over 30 min and the mixture was then heated at reflux for 3 hr. The resultant solution was cooled to 20° C., anhydrous ethanol (31.5 g, 0.69 mol) was carefully added and the mixture was then heated at reflux for 1 hr. The cooled solution was poured into water (400 ml) and the separated dichloromethane layer was evaporated to give mainly ethyl cis-4-n-butylcyclohexanecarboxylate (13, 56.4 g), as a viscous oil.

1. filtrationThe catalyst was filtered
2. customthe solution evaporated in vacuo