英文别名Tadalafil Impurity 31; (1R,3R)-1-(1,3-benzodioxol-5-yl)-2-(2-chloroacetyl)-2,3,4,9-tetrahydro-1H-Pyrido[3,4-b]indole-3-carboxylic acid; Tadalafil Impurity 39; 1H-Pyrido[3,4-b]indole-3-carboxylic acid, 1-(1,3-benzodioxol-5-yl)-2-(2-chloroacetyl)-2,3,4,9-tetrahydro-, (1R,3R)-; TDF-M2-COOH; TDF-DA-M2-COOH impurity