Citric Acid → HCID 59841868, compound

Participants

Reaction Steps

To a solution of Citrulline (2.54 g, 14.50 mmole) and Sodium Bicarbonate (1.28 g) in water (40 mL) was added Boc-Val-OSu (4.34 g, 13.81 mmole) dissolved in dimethoxyethane (DME). To aid the solubility of the mixture tetrahydrofuran (10 mL) was added. The mixture thus obtained was let stir overnight at room temperature. Aqueous citric acid (15%, 75 mL) was added and the mixture was extracted with 10% 2-propanol/ethyl acetate (2×100 mL). The organic layer was washed with brine (2×150 mL) and the solvents were removed on the rotovap. The resulting white solid was dried in vacuo for 5 hours and then treated with ether (100 mL). After brief sonication and trituration, the white solid product was collected by filtration (1.39 g, 27%). 1H NMR (CD3OD) δ 0.91 (dd, 3H), 0.98 (dd, 3H), 1.44 (s, 9H), 1.70 (m, 2H), 1.87 (m, 2H), 2.02 (m, 2H), 3.11 (t, 2H), 3.89 (t, 1H), 4.39 (q, 1H), 8.22 (d, 1H) ppm; LC-MS (ESI) 375 (M+H+).

Provenance & Evidence