Chlorosulfonyl isocyanate → 1-(5-(4-(Benzylamino)-5-phenylphthalazin-1-yl)pyridin-3-yl)urea

Participants

Reaction Steps

To a solution of 4-(5-aminopyridin-3-yl)-N-benzyl-8-phenylphthalazin-1-amine (60.0 mg, 0.149 mmol) in dichloromethane (10 mL) was added chlorosulfonyl isocyanate (0.0191 mL, 0.223 mmol) dropwise at 0° C. and the reaction mixture allowed to stir for 2 h while warming to ambient temperature. The volatile components were evaporated under reduced pressure and the resulting residue was cooled to 0° C. 1.5N HCl was added and the reaction mixture stirred for an additional 2 h. The reaction mixture was adjusted to pH˜8 by the addition of aqueous sodium bicarbonate. The resulting solution was extracted with ethyl acetate (3×5 mL). The combined organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. The resulting residue was purified by preparative HPLC (Condition 30 as described in general methods) to afford 1-(5-(4-(benzylamino)-5-phenylphthalazin-1-yl)pyridin-3-yl)urea (2.00 mg, 3.01%) as a white solid. LCMS (Condition 4): retention time 2.32 min, [M+1]=447.2. HPLC (Condition 28): retention time=6.13 min, purity 98.80%. 1H NMR (400 MHz, DMSO-d6) δ 4.51 (d, J=4.8 Hz, 2 H), 5.04 (t, J=4.8 Hz, 1 H), 6.10 (s, 2 H), 7.02 (dd, J=1.2 Hz, J=6.8 Hz, 2 H), 7.22-7.28 (m, 3 H), 7.43-7.51 (m, 5 H), 7.68 (dd, J=1.2 Hz, J=7.6 Hz, 1 H), 7.85-7.92 (m, 2 H), 8.24 (dd, J=2.0 Hz, J=2.4 Hz, 1 H), 8.37 (d, J=2.0 Hz, 1 H), 8.64 (d, J=2.4 Hz, 1 H), 8.94 (s, 1 H).

Provenance & Evidence