Dicyclohexylcarbodiimide → 1-Benzyl-3(S)-n-butylpiperazine-2,5-dione

HRID 1598442Notes

Reaction equation

HRID 1598442 reaction equation
[C:1]([NH:8][C@H:9]([C:14]([OH:16])=O)[CH2:10][CH2:11][CH2:12][CH3:13])([O:3]C(C)(C)C)=O.[CH2:17]([NH:24][CH2:25]C(OCC)=O)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C1(N=C=NC2CCCCC2)CCCCC1>>[CH2:17]([N:24]1[CH2:25][C:1](=[O:3])[NH:8][C@@H:9]([CH2:10][CH2:11][CH2:12][CH3:13])[C:14]1=[O:16])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

4

Reactant 3

HCID 10868DicyclohexylcarbodiimideHCID 80908N-Benzylglycine ethyl esterHCID 2733747N-tert-Butoxycarbonyl-L-norleucine

Product 1

HCID 600090831-Benzyl-3(S)-n-butylpiperazine-2,5-dioneYield 102%

Procedure

The title compound was prepared according to the procedure described in Example 2, Step A, except using Boc-L-norleucine (10.5 g, 45.2 mmol), ethyl N-benzylglycinate (8.72 g, 45.2 mmol) and dicyclohexylcarbodiimide (9.33 g, 45.2 mmol). The crude diketopiperazine was triturated with hexane to give the title compound as a white powder (12.0 g). NMR (300 MHz, CDCl3) δ 7.24-7.40 (5H, m), 6.22 (1H, br s), 4.07 (1H, dt, J=3, 6 Hz), 3.87 (1H, d, J=17 Hz), 3.80 (1H, d, J=17 Hz), 1.88 (2H, m), 1.35 (4H, m), 0.91 (3H, t, J=7 Hz).

Workup

  1. customThe title compound was prepared
  2. customThe crude diketopiperazine was triturated with hexane

Sources & evidence

ORD record
ord-32de742fb1e2403992e598c212ab6f0b
Source dataset
uspto-grants-1998_04
Patent number
US05736539

Reaction notes

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