To a stirred solution of N-(3-aminophenyl)-3-(dimethylamino)propanamide (1.15 g, 5.5 mmol) in dry DMF (20 mL) containing TEA (1.6 mL) was added a solution of N,N-bis(2-chloroethyl)-4-isocyanatoaniline [7, freshly prepared from N1,N1-bis-(2-chloroethyl)benzene-1,4-diamine hydrochloride 6 (3.4 g, 11 mmol) and triphosgene in chloroform] in dry DMF (5 mL)) at room temperature. After being stirred overnight at room temperature, the solid was filtered and washed with dry DMF. The filtrate was evaporated to dryness in vacuo and the product was purified by column chromatography using CHCl3/MeOH (100:10 v/v) as an eluent. The fractions containing main product were combined and evaporated to dryness under vacuum to afford compound N-(3-(3-(4-(bis(2-chloroethyl)amino)-phenyl)ureido)phenyl)-3-(dimethylamino)-propanamide (BO-2091), 2.2 g (62%); mp 88-90° C. The HCl salt of BO-2091 was prepared by treating the compound with HCl/EtOAc in a mixture of EtOAc:MeOH (10:1, v/v, 50 mL) under argon atmosphere during 30-40 min at room temperature. Solvent was then evaporated to dryness to give HCl salt of BO-2091. 1H NMR (DMSO-d6) δ: 2.77 (6H, s, CH3), 2.84-2.87 (2H, t, J=7.1 Hz, CH2), 3.32-3.35 (2H, t, J=6.7 Hz, CH2), 3.68-3.70 (8H, m, CH2), 6.71-6.73 (2H, d, J=8.6 Hz, Ar—H), 7.27-7.29 (2H, d, J=8.8 Hz, Ar—H), 7.36-7.38 (2H, d, J=8.8 Hz, Ar—H), 7.48-7.50 (2H, d, J=8.8 Hz, Ar—H), 7.95 (1H, brs, NH), 8.82 (1H, brs, NH), 9.02 (1H, brs, NH). 13C NMR (CDCl3, 125 MHz) δ: 30.50, 41.00, 42.10, 52.52, 52.58, 112.95, 117.95, 119.74, 120.02, 130.64, 132.64, 135.77, 140.96, 152.85, 167.25. HRMS [ES+]: calcd for C22H29Cl2N5O2, 466.4040 [M+H]+. found 466.1771. HPLC 98.7%.
