Dicyclohexylcarbodiimide → (S)-1,3-Dibenzylpiperazine-2,5-dione

反応式

[C:1]([NH:8][C@H:9]([C:17]([OH:19])=O)[CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)([O:3]C(C)(C)C)=O.[CH2:20]([NH:27][CH2:28]C(OCC)=O)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.C1(N=C=NC2CCCCC2)CCCCC1>>[CH2:20]([N:27]1[CH2:28][C:1](=[O:3])[NH:8][C@@H:9]([CH2:10][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:17]1=[O:19])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

参加物

反応物 3

HCID 10868Dicyclohexylcarbodiimide

HCID 77857L-Phenylalanine, N-[(1,1-dimethylethoxy)carbonyl]-

HCID 80908N-Benzylglycine ethyl ester

生成物 1

HCID 10708931(S)-1,3-Dibenzylpiperazine-2,5-dione収率 88.1%

実験手順

The title compound was prepared according to the procedure described in Example 2, Step A, except using Boc-L-phenylalanine (12.8 g, 48.2 mmol), ethyl N-benzylglycinate (9.32 g, 48.2 mmol) and dicyclohexylcarbodiimide (96.5 mL 0.5M in dichloromethane, 48.2 mmol). The crude diketopiperazine was triturated with hexane to give the title compound as a white powder (12.5 g). NMR (300 MHz, CD3OD) δ 7.0-7.4 (10H, m), 4.61 (1H, d, J=16 Hz), 4.37 (1H, t, J=5 Hz), 4.24 (1H, d, J=16 Hz), 3.42 (1H, d, J=18 Hz), 3.28 (1H, dd, J=4, 16 Hz), 2.96 (1H, dd, J=6, 16 Hz), 2.55 (1H, d, J=18 Hz).