Sodium hydride → N-(4-Cyanobenzyl)-L-pyroglutamic acid methyl ester

Reaction equation

[CH3:1][O:2][C:3](=[O:10])[C@@H:4]1[CH2:8][CH2:7][C:6](=[O:9])[NH:5]1.[H-].[Na+].[C:13]([C:15]1[CH:22]=[CH:21][C:18]([CH2:19]Br)=[CH:17][CH:16]=1)#[N:14]>C1COCC1>[CH3:1][O:2][C:3](=[O:10])[C@@H:4]1[CH2:8][CH2:7][C:6](=[O:9])[N:5]1[CH2:19][C:18]1[CH:21]=[CH:22][C:15]([C:13]#[N:14])=[CH:16][CH:17]=1

Participants

Procedure

L-Pyroglutamic acid methyl ester (1.36 g, 0.0095 mol) was dissolved in dry THF (20 mL) under Ar, treated with NaH (60% oil dispersion) (0.58 g, 0.0145 mol) with stirring for 5 min, then the mixture was cooled to 0° C. p-Cyanobenzylbromide (1.78 g, 0.0091 mol) was added, and the mixture left to slowly warm to ambient temperature. After 48 h the reaction mixture was partitioned between EtOAc and satd NaHCO3 solution, the aqueous layer separated and washed with CH2Cl2, the organics combined, washed with brine and dried (MgSO4). Filtration and concentration to dryness followed by trituration with ether gave the white solid product. 1H NMR(CDCl3, 400 MHz) δ 7.62(2H, d, J=8 Hz), 7.33(2H, d, J=8 Hz), 4.98(1H, d, J=15.4 Hz), 4.13(1H, d, J=15.4 Hz), 3.99(1H, dd, J=3, 9 Hz) and 2.5-2.6 (1H, m), 2.4-2.5 (1H, m), 2.2-2.45 (1H, m), 2.1-2.2 (1H, m) ppm.