Acetic Acid → HCID 131727254, compound

Participants

Reaction Steps

This procedure is based on the method used by Gallina et al. to synthesize a series of Z-hydrazines [Calbretta et al, Eur. J. Med. Chem. 30, 931 -941 (1995); incorporated herein by reference]. PhPr-Leu-NH—N═CH(CH2)2—NH-Boc (1.928 g, 4.46 mmol) and NaBH3CN (5 eq, 1.400 g, 22.3 mmol) were dissolved in anhydrous THF (23 mL). Glacial acetic acid (104 eq, 27.85 g, 464 mmol, 26.5 mL) was added dropwise to the solution, and the reaction mixture was allowed to stir at rt overnight. The solvents were evaporated and the crude oil dissolved in ethyl acetate (20 mL). Distilled water (20 mL) was added to the solution, which was vigorously stirred while enough solid NaHCO3 was added to turn the pH of the aqueous layer basic. The organic layer was isolated and washed with a saturated NaCl solution (2×15 mL), a saturated NaHCO3 solution (10 mL), and again with a saturated NaCl solution (10 mL). The organic layer was dried over MgSO4, filtered, and evaporated. The crude solid was purified by silica gel chromatography using 1/1 ethyl acetate/hexanes as the eluent. The solvent was evaporated, leaving a white, foamy solid that was used without further purification: yield 59%; product spot on TLC, Rf=0.43 (10% CH3OH in CH2Cl2). 1H NMR (CDCl3) δ 9.80 (s, 1H), 9.54 (s, 1H), 7.30-7.13 (m, 5H), 6.94 (s, 1H), 6.60 (s, 1H), 4.60-4.47 (m, 1H), 3.25-3.06 (m, 2H), 3.04-2.93 (m, 4H), 2.60-2.51 (m, 2H), 2.87-1.72 (m, 3H), 1.70-1.60 (m, 2H), 1.42 (s, 9H), 0.98-0.82 (m, 6H). MS (ESI+) m/z 435 (M+1).

Provenance & Evidence