Dichloromethane → Tadalafil Impurity 11

Participants

Reaction Conditions

Reaction Steps

D-tryptophan methyl ester hydrochloride (100 g) and piperonal (65 g) were suspended in sulfolane (500 mL) at 25-30° C. The reaction mixture was heated to 80-85° C., stirred for 14 hours and then cooled to 25-30° C. To the cooled mixture dichloromethane (500 mL) was added and the resultant mixture stirred continuously for 1 hour. The solid obtained was filtered, washed with dichloromethane (500 mL) and dried in air at 40-45° C. to afford cis 1-benzo [1,3 ]dioxol-5 -yl-2,3,4,9-tetrahydro-1H-beta-carboline-3 -carboxylic acid methyl ester hydrochloride.

Provenance & Evidence