A solution of benzyl 3-(7-methyl-1H-indazol-5-yl)-1-(neopentylamino)-1-oxopropan-2-ylcarbamate (0.17 g, 0.402 mmol) in chloroform (0.5 mL) was added to a mixture of phosphorus pentachloride (0.17 g, 0.802 mmol) and quinoline (0.2 mL) in chloroform (1.0 mL). After stirring at room temperature for 2 h, the solvents were removed in vacuo. The crude mixture was dissolved in acetonitrile (2.0 mL) and treated with sodium azide (78 mg, 3.0 equiv). After stirring the mixture at 40° C. overnight, the solvents were removed and the crude mixture dissolved in methylene chloride which was washed with water (2×), brine (2×), dried over sodium sulfate, and concentrated. Column chromatography afforded 73 mg (40%, 2 steps). 1H-NMR (CD3OD, 500 MHz) δ 0.82 (s, 9H), 2.46 (s, 3H), 2.30-3.46 (m, 2H), 3.69 (d, J=14.3, 1H), 3.93 (d, J=14.3, 1H), 4.98-5.13 (m, 2H), 5.30 (m, 1H), 6.02 (d, J=8.9, 1H), 6.86 (s, 1H), 7.25-7.35 (m, 5H), 7.94 (s, 1H). Mass spec.: 448.19 (MH)+.
