Trityl chloride → tert-butyl (4S)-4-{[3-(tert-butoxycarbonylamino)propionyl]amino}-5-{[1-methyl-5-(tritylamino)-1H-pyrazol-4-yl]amino}-5-oxopentylcarbamate

Participants

Reaction Steps

To a solution of the crude product of tert-butyl (4S)-5-[(5-amino-1-methyl-1H-pyrazol-4-yl)amino]-4-{[3-(tert-butoxycarbonylamino)propionyl]amino}-5-oxopentylcarbamate and triethylamine (1.52 g) in chloroform (100 ml) was added triphenylmethyl chloride (4.20 g), and the mixture was stirred at room temperature for 1 hour. The reaction mixture was washed successively with 10% aqueous citric acid solution, brine and saturated aqueous sodium hydrogencarbonate solution. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to give tert-butyl (4S)-4-{[3-(tert-butoxycarbonylamino)propionyl]amino}-5-{[1-methyl-5-(tritylamino)-1H-pyrazol-4-yl]amino}-5-oxopentylcarbamate (7.20 g) as an oil.

Provenance & Evidence