4-Methylmorpholine → HCID 13685983, compound

Participants

Reaction Steps

N-(4-fluorobenzyloxycarbonyl)-L-prolyl-L-valinol was prepared from 16.1 g (60.2 mmol) p-fluorobenzyloxycarbonyl-L-proline, 8.22 g (60.2 mmol) isobutyl chloroformate, 6.09 g (60.2 mmol) N-methylmorpholine, and 6.21 g (60.2 mmol) L-valinol, substantially according to the mixed anhydride procedure described in Example 1. The resulting crude product (19.46 g) was recrystallized from a mixture of 100 mL ethyl acetate and 200 mL n-hexane to give 16.69 g (47.4 mmol, 78.7%) of N-(4-fluorobenzyloxycarbonyl)-L-prolyl-L-valinol, m.p. 123°-124°. αD25 -60.2° (C=1.02 g/100 mL in acetone). An nmr obtained for this material spectrum verified the assigned structure: 1H NMR (CDCl3 /TMSi), 220 mc, δ0.85, m, 6H (valinol CH3); δ1.9, m, 2H (proline γ-CH2); δ2.2, m, 3H (valinol β-CH and proline β-CH2); δ 3.35, m, 3H (proline δCH2); δ 3.58, m, 2H (CH2OH); δ 4.34, m, H (valinol α-CH); δ 5.0, s, 2H (benzyl CH2); δ 6.30-6.80, m, H (NH); δ 7.03, m, 2H (aromatic); δ 7.35, m, 2H (aromatic).

Provenance & Evidence