Reaction Steps
To a solution of dansyl chloride (270 mg, 1.00 mmol) in CH2Cl2 (10 mL) was added 4-aminobutyraldehyde diethyl acetal (237 μL, 1.20 mmol) and Et3N (170 μL, 1.20 mmol). The solution was stirred for 1 h at 25° C. and was then evaporated to dryness under reduced pressure. The material left was processed and purified under conditions identical to those described for the processing and purification of 11. Fractions containing the product were collected and evaporated to dryness under low pressure affording 13 (366 mg, 930 μmol) as a solid in a yield of 93%. 1H NMR (300 MHz, DMSO-d6): δ 8.45 (dt, J=8.5, 1.1 Hz, 1H), 8.30 (dt, J=8.8, 0.9 Hz, 1H), 8.09 (dd, J=7.3, 1.2 Hz, 1H), 7.89 (t, J=5.5 Hz, 1H), 7.61 (t, J=8.5 Hz, 1H), 7.58 (t, J=8.5 Hz, 1H), 7.25 (dd, J=7.6, 0.7 Hz, 1H), 4.19 (t, J=5.3 Hz, 1H), 3.36 (m, 2H), 3.23 (m, 2H), 2.81 (s, 6H), 2.77 (t, J=5.5 Hz, 2H), 1.31 (m, 4H), 0.99 (t, J=7.0 Hz, 6H). 13C NMR (75 MHz, DMSO-d6): δ 151.2, 136.1, 129.2, 128.9, 128.1, 127.7, 123.5, 119.1, 114.9, 101.6, 60.2, 44.9, 42.2, 30.1, 24.4, 15.1. +ESI-HRMS: Calcd for C20H30N2O4S [M+H]+ 395.1999. found 395.2000.
