Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → tert-butyl 2-amino-4-[(1R)-1-({[(6S)-6-(5-chloro-2-methoxybenzyl)-7-oxo-6,7-dihydro-5H-imidazo[1,2-a][1,4]diazepin-8(9H)-yl]carbonyl}amino)propyl]benzoate

Participants

Reaction Conditions

Reaction Steps

The compound 89a crude product obtained at Step (1) (94.2 mg) was dissolved in 1,4-dioxane (4 ml), pyridinium p-toluenesulfonate (5 mg) was added, and the mixture was stirred at 100° C. for 2 hours. The reaction solution was concentrated, then the residue was purified by flash column chromatography (NH2 silica gel, ethyl acetate/hexane=7/3 to 1/0) to obtain tert-butyl 2-amino-4-[(1R)-1-({[(6S)-6-(5-chloro-2-methoxybenzyl)-7-oxo-6,7-dihydro-5H-imidazo[1,2-a][1,4]diazepin-8(9H)-yl]carbonyl}amino)propyl]benzoate (compound 89b) (33.4 mg).

Provenance & Evidence