Triethylamine → HCID 69269265, compound

Participants

Reaction Steps

A flask was charged with 2.19 g (6.71 mmol) of (S)-2-((R)-4-cyclohexyl-2-methyl-butyl)-succinic acid 4-tert-butyl ester, 40 mL of toluene, 0.935 mL (6.71 mmol) of triethylamine, and 1.45 mL (6.71 mmol) of diphenylphosphorylazide. The mixture was stirred for 15 minutes at room temperature and then heated to 110° C. and stirred for 6 hours. The toluene was removed under reduced pressure, and the residue was taken up in diethyl ether. The ether layer was washed with 3M HCl aq., water, and brine. The ether was removed under reduced pressure, and the crude isocyanate was taken up in 3 M HCl aq. and heated at reflux for 8 hours. The water was removed under reduced pressure, and the residue was triturated with ether. This provided 1.45 g of an impure white solid. A portion of the white solid was dissolved in methanol, and HCl gas was bubbled through for 15 minutes. The acidic solution was stirred 2 hours. The methanol was removed under reduced pressure, and the crude ester was purified by column chromatography (4:1 dichloromethane: methanol). This gave 0.356 g of the pure ester: 1H NMR (400 MHz, CDCl3) δ ppm 0.85 (m, 2 H) 0.88 (d, J=8.00 Hz, 3 H) 1.15 (m, 6 H) 1.26 (m, 1 H) 1.36 (ddd, J=13.73, 9.21, 4.64 Hz, 1 H) 1.51 (m, 1 H) 1.65 (m, 7 H) 2.28 (dd, J=15.86, 8.78 Hz, 1 H) 2.43 (dd, J=16.0, 4.00 Hz, 1 H) 3.28 (m, J=8.97, 8.97, 4.39, 4.27 Hz, 1 H) 3.69 (s, 3H). MS (APCl) m+1/z=256.

Provenance & Evidence