Phosgene → 4-(1-benzyl-2-oxo-2,3-dihydro-1H-benzoimidazol-4-yl)-piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of 4-(2-amino-3-benzylamino-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (0.176 g, 0.459 mmol) in 1 mL dichloromethane was added 1 mL of 2M aqueous sodium carbonate. Phosgene (0.261 mL of a 1.93 M solution in toleuene, 0.504 mmol) was added dropwise to the stirring solution over five minutes. Stirring was continued for two hours as a fine white precipitate was formed. The solid was filtered and dried under a stream of nitrogen to give 0.112 g of 4-(1-benzyl-2-oxo-2,3-dihydro-1H-benzoimidazol-4-yl)-piperazine-1-carboxylic acid tert-butyl ester as a fine white powder. MS: 409 (M+H)+.

Provenance & Evidence