p-Toluenesulfonic acid → HCID 5194456, compound

Participants

Reaction Steps

A mixture of compound from Example 6 (31 g, 0.21 mol), 4-bromobenzaldehyde (38.8 g, 0.21 mol) and 4-toluenesulphonic acid (110 mg) in dry toluene (200 cm3) was heated under reflux (3 h) using a Dean and Stark apparatus. On cooling to room temperature the mixture was poured into aqueous sodium hydrogen carbonate solution (5%, 70 cm3) and the separated organic layer washed with aqueous sodium hydrogen carbonate solution (5%, 2×60 cm3), water (2×60 cm3) and dried (MgSO4). The solvent was removed in vacuo and the residue purified by crystalliation from methanol to remove the cis-isomer.

Provenance & Evidence