p-Toluenesulfonic acid → HCID 15672405, compound

Participants

Reaction Steps

A solution of dimethyl 5-formylpyridine-2,3-dicarboxylate (0.73 g, 0.00327 mol), ethanedithiol (0.357 mL, 0.00425 mol) and a catalytic amount of para-toluenesulfonic acid in chloroform (20 mL) is heated at reflux for 5.5 hours. During this time, water is removed by placement of an addition funnel containing 3 angstrom molecular sieves in between the reaction flask and the reflux condensor. After cooling, the reaction is diluted with methylene chloride (20 mL) and is washed with 10% aqueous sodium carbonate and saturated sodium chloride solutions. The organic solution is dried over anhydrous magnesium sulfate and concentrated in vacuo to give a residue. The residue is purified by chromatography using silica gel and 33% ethyl acetate in hexanes as eluant to yield the title compound as a clear oil (0.66 g, 67%), identified by IR and NMR spectral analyses.

Provenance & Evidence