Triphosgene → (2S)-dimethyl 2-(3-(4-(6,8-dichloro-2-methyl-1,2,3,4-tetrahydroisoquinolin-4-yl)phenyl)ureido)succinate

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Reaction Conditions

Reaction Steps

Into a 50-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of 4-(6,8-dichloro-2-methyl-1,2,3,4-tetrahydroisoquinolin-4-yl)benzenamine (intermediate 30.7) (200 mg, 0.65 mmol, 1.00 equiv) in dichloromethane (10 mL), triethylamine (1.2 mL). This was followed by the addition of bis(trichloromethyl) carbonate (200 mg, 0.67 mmol, 1.03 equiv) slowly with stirring at 0-5° C. The resulting solution was stirred for 1 h at room temperature. To this was added triethylamine (1 mL) followed by (S)-dimethyl 2-aminosuccinate (200 mg, 1.24 mmol, 1.91 equiv) in several batches. The resulting solution was stirred for 2 h at room temperature. The resulting mixture was concentrated under vacuum and the residue was applied onto a silica gel column and eluted with ethyl acetate/petroleum ether (1:10-1:5). This resulted in 50 mg (15%) of (2S)-dimethyl 2-(3-(4-(6,8-dichloro-2-methyl-1,2,3,4-tetrahydroisoquinolin-4-yl)phenyl)ureido)succinate as yellow oil.

Provenance & Evidence