Methylamine → Tadalafil

Participants

Reaction Steps

Cis-1-benzo[1,3]dioxol-5-yl-2-(2-chloro-acetyl)-2,3,4,9-tetrahydro-1H-beta-carboline-3-carboxylic acid methyl ester of Step 3 (30 g) was taken in methanol (450 ml). The resultant mixture was heated to 35° C. to 40° C. and aqueous methyl amine (27 ml; 40%) was added. The reaction mixture was stirred at 50° C. to 55° C. for 5 hours and then cooled to 10° C. to 15° C. with continuous stirring for 0.5 hours. The solid so obtained was filtered and dried to afford (6R,12 aR)-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydro-2-methylpyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione.

Provenance & Evidence