p-Toluenesulfonic acid → HCID 178441532, compound

Participants

Reaction Steps

A mixture of 1.75 g of 4-methoxy-o-phenylenediamine, 2 mL of triethylamine and a catalytic amount of p-dimethylaminopyridine in 20 mL of methylene chrloride was cooled with ice. To the above solution was added 1.3 mL of valeryl chloride dropwise. The reaction mixture was stirred at room temperature for 2 hours and diluted with 100 mL of ethyl acetate, then washed with water and concentrated to give a crude product which was dissolved in 30 mL of absolute ethanol. After 2 mL of glacial acetic acid and a catalytic amount of p-toluenesulfonic acid were added to the above, the solution was refluxed for 18 hours. The reaction mixture was concentrated and the residue was purified by flash column chromatography on silica gel (100% EtOAc elution) to give 0.46 g of the desired product as a thick colorless oil.

Provenance & Evidence