Potassium Carbonate → Boc-serinol Bisphthalonitrile

Participants

Reaction Steps

Finely ground K2CO3 (4.32 g, 31.2 mmol, 4 equiv.) was added to N-Boc-serinol (1.45 g, 7.8 mmol, 1 equiv.) in 20 mL DMSO under argon; then 3-nitrophthalonitrile (3.38 g, 19.5 mmol, 2.5 equiv.) was added. The reaction mixture first turned pink, and then orange upon addition of the 3-nitrophthalonitrile. The reaction mixture was stirred at room temperature and monitored periodically by TLC (9:1 benzene:CH3CN). After 72 h, the reaction mixture was partitioned between EtOAc and water. The two layers were separated, and the aqueous layer was extracted 3 times with 50 mL EtOAc. The organic layer from the original partitioning was added to the organic extract. This mixture was then washed twice with 50 mL of saturated NaHCO3, and twice with 50 mL of water, and was then dried over Na2SO4. The solvent was removed at reduced pressure, and the resulting crude orange solid was recrystallized from methanol/water to give 2.43 g (70% yield) of a slightly pink/tan solid. [Rf: 0.25 (9:1 benzene:CH3CN); melting point 167-169° C.; 1H NMR (200 MHz, CD3CN) δ 7.85-7.4 (m, 6H, ArH), 5.76 (br s, 1H, NH), 4.39 (s, 5H, (—CH2)2CH—), 1.42 (s, 9H, C(CH3)3).]

Provenance & Evidence