Benzene → HCID 53971628, compound

Participants

Reaction Steps

4-Diethylaminosalicylaldehyde (25.0 g, 129 mmol; Tokyo Kasei Ind. Co. Ltd.) and carboxymethylidene-triphenylphosphorane (49.0 g, 140 mmol; Aldrich Inc.) were stirred in 300 ml of anhydrous benzene at room temperature overnight under a nitrogen atmosphere and the reaction was allowed to complete, during which period the reaction was conducted in a dark room. Then, the solvent was removed in vacuo, and the resulting crude product was crudely purified by silica gel column chromatography (hexane/ethyl acetate 1:1 as a developing solvent) to give a mixture of cis- and trans-isomers. Further, this mixture was purified by column chromatography using aminopropyl-modified silica gel (300 g of NHDM-1020 silica gel available from Fuji Silicia Chemicals Co. Ltd; n-hexane/ethyl acetate 2:1 which elutes only the cis-isomer and chloroform/methanol 4:1 which elutes only the trans-isomer) to give 23.7 g of the desired product in 70% yield.

Provenance & Evidence