Dimethylamine → 7-(4-Dimethylcarbamoyl-phenoxy)-3,4-dihydro-1H-isoquinoline-2-carboxylic acid benzyl ester

Participants

Reaction Steps

2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (0.44 g) is added to a solution of 7-(4-carboxy-phenoxy)-3,4-dihydro-1H-isoquinoline-2-carboxylic acid benzyl ester, dimethylamine (2 mol/L in tetrahydrofuran, 0.68 mL), and N-methyl-morpholine (0.41 mL) in tetrahydrofuran (20 mL) chilled in an ice bath. The cooling bath is removed and the resulting mixture is stirred at room temperature for 3 h. Then another portion of dimethylamine (2 mol/L in tetrahydrofuran, 0.70 mL) and 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (0.20 g) are added and the mixture is further stirred for another 4 h. After adding another portion of dimethylamine (2 mol/L in tetrahydrofuran, 0.30 mL), the mixture ist stirred at room temperature overnight. The mixture is concentrated and the residue is purified by chromatography on silica gel (ethyl acetate) to furnish the title compound.

Provenance & Evidence