Benzene → HCID 19041740, compound

Participants

Reaction Steps

1-(3,5-dimethoxy-4-hydroxyphenyl)-1,2-ethanedithiol (40) (2.10 g, 8.54 mmole), 3,4,5-trimethoxybenzaldehyde (24) (1.28 g, 6.57 mmole) and 0.857 g of pyridinium paratoluene sulfonate are added to 60 ml dry benzene and refluxed with Dean-Stark removal of the benzene-water azeotrope overnight. The benzene is removed in vacuo, and the remaining oil is extracted into 10% NaOH which was washed with diethylether. The basic layer is reacidified with 10% HCl and the desired product is extracted into ethyl acetate. The organic layer is dried over MgSO4, filtered, and evaporated in vacuo to an oil which is purified by flash column chromatography with 2:1 hex/ethyl acetate as eluent. The product mixture contains a 1.0/1.2 cis/trans ratio after the first recrystallization (1.287 g, 59%). The trans isomer is isolated after six additional recrystallizations from methanol.

Provenance & Evidence