Glycine → (2S)-2-amino-5-(tert-butoxy)-5-oxopentanoic acid

HRID 1421365Notes

Reaction equation

HRID 1421365 reaction equation
[NH2:1][C@H:2]([C:4]([OH:6])=[O:5])[CH3:3].N[C@H:8]([C:19]([OH:21])=[O:20])CC1C2C(=CC=CC=2)NC=1.NCC(O)=O.N[C@H:28](C(O)=O)[CH:29]([CH3:31])[CH3:30].N[C@H](C(O)=O)[C@H](CC)C>>[NH2:1][C@H:2]([C:4]([OH:6])=[O:5])[CH2:3][CH2:8][C:19](=[O:20])[O:21][C:29]([CH3:31])([CH3:30])[CH3:28]

Participants

6

Reactant 5

HCID 750GlycineHCID 5950L-AlanineHCID 6287L-ValineHCID 6305L-TryptophanHCID 6306L-Isoleucine

Product 1

HCID 7010573(2S)-2-amino-5-(tert-butoxy)-5-oxopentanoic acid

Procedure

The inability to crystallize some of the above-mentioned derivatives led to the preparation of corresponding 3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl (ODhbt) esters. The Ddz-Xxx-ODhbt esters of Ala, Pro, and Trp were easily prepared as crystalline solids, followed by Gly, Val, and Ile. In addition, the ODhbt esters of Ser and Thr were crystallized upon preparation, whereas Leu, Met, Phe, Cys(Stbu), Asp(tBu), and Glu(tBu) were obtained as foams. Ddz-Arg-(Pmc)Dhbt was isolated in about 92% purity including 5-6% of the γ-lactam impurity. Ddz-Arg(Pmc)Pfp was also isolated, but with somewhat less γ-lactam impurity. Examples of derivatives prepared are summarized in Table 1 and the examples.

Workup

  1. customThe inability to crystallize some of the above-mentioned derivatives
  2. customled to the preparation of corresponding 3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl (ODhbt) esters
  3. customIn addition, the ODhbt esters of Ser and Thr were crystallized upon preparation, whereas Leu, Met, Phe, Cys(Stbu), Asp(tBu)

Sources & evidence

ORD record
ord-9f23f5452d514d9b88c749dd99aaf80f
Source dataset
uspto-grants-2000_06
Patent number
US06075141

Reaction notes

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