Water → N-benzhydryloxycarbonyl-L-leucine

HRID 65602Notes

Reaction equation

HRID 65602 reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5].[O-2].[Mg+2].O.[CH:13]([O:26][C:27](N=[N+]=[N-])=[O:28])([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>O1CCOCC1>[CH:13]([O:26][C:27]([NH:1][C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH:4]([CH3:6])[CH3:5])=[O:28])([C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 4

HCID 962WaterHCID 6106L-LeucineHCID 76824Carbonazidic acid, diphenylmethyl esterHCID 6850729Magnesium monoxide

Product 1

HCID 53905484N-benzhydryloxycarbonyl-L-leucine

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a mixture consisting of 13.1 g. of L-leucine, 6 g. of magnesium oxide, and 150 ml. of water is added a solution of 25.3 g. of benzhydrylazidoformate in 150 ml. of dioxane, and the resulting mixture is stirred at room temperature for 2 days. It is then filtered, and the filtrate is concentrated to remove the dioxane. The aqueous concentrate is acidified with solid citric acid, and the acidified mixture is extracted with ethyl acetate. The extract is dried and evaporated to dryness to give an oily residue of N-benzhydryloxycarbonyl-L-leucine, which is suitable for use without further purification. To a mixture of 32 g. of this intermediate product, 25 g. of pentachlorophenol, and 300 ml. of ethyl acetate, at 5° C., is added 20 g. of dicyclohexylcarbodiimide, and the resulting mixture is kept at 5° C. for 5 hours and filtered. The filtrate is concentrated to small volume, and the concentrate is treated with petroleum ether to give a precipitate of N-benzhydryloxycarbonyl-L-leucine pentachlorophenyl ester, which is isolated and crystallized from ethanol-water; m.p. 84°-86° C.; [α]D25 -27.8° (2% in methanol).

Workup

  1. filtrationIt is then filtered
  2. concentrationthe filtrate is concentrated
  3. customto remove the dioxane
  4. concentrationThe aqueous concentrate
  5. extractionthe acidified mixture is extracted with ethyl acetate
  6. customThe extract is dried
  7. customevaporated to dryness

Sources & evidence

ORD record
ord-425924a57b5d452b968463cd2d36b7eb
Source dataset
uspto-grants-1978_12
Patent number
US04128540

Reaction notes

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