Phosgene → 4-[Bis-(3-methyl-pyridin-2-ylmethyl)-amino]-piperidine-1-carboxylic acid benzyl-hydroxy-amide

Participants

Reaction Steps

To a solution of COMPOUND 249 (0.115 g, 0.37 mmol) in toluene (4 mL) was added DIPEA (0.16 mL, 0.92 mmol) followed by phosgene solution (20% in toluene, 0.20 mL, 0.44 mmol). The resultant mixture was stirred at room temperature for 90 minutes then concentrated under reduced pressure. The residue was dissolved in DMF (4 mL) and treated with DIPEA (0.60 mL, 3.44 mmol) followed by N-benzylhydroxylamine hydrochloride (0.194 g, 1.22 mmol) and the resultant mixture was stirred at room temperature overnight. The mixture was concentrated and the residue was partitioned between CH2Cl2 (50 mL) and saturated aqueous NaHCO3 (15 mL). The phases were separated and the aqueous phase was extracted with CH2Cl2 (3×15 mL). The combined organic extracts were dried (Na2SO4) and concentrated. Purification of the crude material by radial chromatography on silica gel (1 mm plate, 25:1:1 CH2Cl2-MeOH—NH4OH) provided 131 mg (74%) of COMPOUND 272 as a white solid. 1H NMR (CDCl3) δ 1.64-1.76 (m, 2H), 1.918-1.96 (m, 2H), 2.08 (s, 6H), 2.68-2.79 (m, 3H), 3.81 (s, 4H), 4.20 (d, 2H, J=13.2 Hz), 4.30 (s, 2H), 6.81 (s, 1H), 7.08 (dd, 2H, J=7.5, 4.8 Hz), 7.27-7.38 (m, 7H), 8.32 (d, 2H, J=3.6 Hz); 13C NMR (CDCl3) δ 18.35, 27.54, 46.12, 54.86, 57.74, 59.70, 122.87, 127.94, 128.68, 129.35, 133.88, 136.61, 138.59, 146.15, 157.28, 164.68; ES-MS m/z 460 (M+H). Anal. Calcd. For C27H33N5O2.0.2CH2Cl2: C, 68.55; H, 7.06; N, 14.70. Found: C, 68.85; H, 7.21; N, 14.79.

Provenance & Evidence