tert-butyl N-(4-aminobutyl)carbamate → HCID 68186050, compound

A mixture of [(4S)-6-(4-chlorophenyl)-1-methyl-8-(methyloxy)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepin-4-yl]acetic acid (for a preparation see Reference compound H) (1.0 g, 2.5 mmol), HATU (1.9 g, 5 mmol) and DIPEA (0.88 ml, 5 mmol) was stirred for 80 minutes at room temperature, to this was added 1,1-dimethylethyl (4-aminobutyl)carbamate (1.05 ml, 5.0 mmol, available from Aldrich). The reaction mixture was stirred at room temperature for 2 h before it was concentrated. The residue was taken up in dichloromethane and washed with 1N HCl. The aqueous layer was extracted with dichloromethane twice. Organic layer was washed with 1N sodium hydroxide, followed by a saturated solution of sodium chloride, dried over sodium sulphate and concentrated. The residue was purified by flash-chromatography on silica using dichloromethane/methanol 95/5 to give the title compound as a yellow solid (1.2 g). LC/MS (Method D): rt=3.04 min.