Dimethylformamide → HCID 11308069, compound

Participants

Reaction Steps

To a solution of (±)-2-(2-(7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazol-5-yl)-1-(4-(2-oxo-1,2-dihydroquinazolin-3(4H)-yl)piperidine-1-carbonyloxy)ethyl)isonicotinic acid (39.2 mg, 0.057 mmol, 1.0 equiv.) in methylene chloride (0.7 mL) was added a drop of dimethylformamide (catalytic) followed by dropwise addition of oxalyl chloride (2 M in methylene chloride, 0.15 mL, 0.3 mmol, 5 equiv) at room temperature under nitrogen. After 2 h, excess piperidine was added dropwise and the mixture was further stirred for 1 h. The mixture was concentrated to a gel and was suspended in methylene chloride (2 mL). Trifluoroacetic acid (1 mL) was added and the resulting clear tan solution was stirred at room temperature for 6 h. The solvents were removed in vacuo and the residue was partitioned between 1 N sodium hydroxide and ethyl acetate. The layers were separated. The organic layer was washed with brine, dried and concentrated. Purification by flash column chromatography (6% methanol/methylene chloride) afforded the desired product (30.4 mg, 85.4%) as an off-white powder. MS (ESI) [M+H]+=622. 1H-NMR (400 MHz, CDCl3) δ 8.69 (d, J=4.4 Hz, 1H), 7.95 (br., 1H), 7.70 (br., 1H), 7.50-6.80 (m, 6H), 6.68 (br., 1H), 6.05-5.94 (m, 1H), 4.65-3.80 (m, 4H), 3.64 (br., 2H), 3.50-3.18 (m, 2H), 3.18-2.60 (m, 4H), 2.48 (s, 3H), 1.85-1.44 (m, 9H), 1.44-1.10 (m, 4H). HPLC tR=1.79 min.

Provenance & Evidence