Dimethyl Sulfate → (2R)-2-[N-(4-Chlorobenzenesulfonyl)-N-(4-methylaminobenzyl)amino]-4-methylpentanoic acid amide

Participants

Reaction Steps

A solution of (2R)-2-[N-(4-chlorobenzenesulfonyl)-N-(4-aminobenzyl)amino]-4-methyl-pentanoic acid amide (Example 48, 400 mg, 1 mmol), Et3N (0.16 mL, 1.1 mmol), dimethylsulfate (139 mg, 1.1 mmol) in 25 mL of toluene was stirred at rt for 18 h. The reaction was concentrated, then taken into EtOAc and washed with H2O, brine, dried over K2CO3 and concentrated to give a crude mixture of starting material and product. The material was further purified by flash chromatography (SiO2, 35% EtOAc/hexanes) to afford the title compound, 195 mg, in 46% yield. MS (ESI), (M+H)+ 424.1; 1H NMR (CDCl3) δ 7.65 (d, 2H, J=8.0), 7.58 (d, 2H, J=8.2), 7.47 (d, 2H, J=8.0), 7.31 (d, 2H, J=8.5), 6.24 (br s, 1H), 5.16 (br s, 1H), 4.50 (dd, 2H, J=50, 17), 4.27 (t, 1H, J=10), 2.44 (s, 3H), 1.74-1.83 (m, 1H), 1.25-1.33 (m, 1H), 0.93-1.01 (m, 1H), 0.74 (d, 3H, J=7.0), 0.63 (d, 3H, J=7.0).

Provenance & Evidence