Benzyl chloroformate → S-(o-Nitrophenyl)-N-carbobenzyloxy-D-cysteine

HRID 53120Notes

Reaction equation

HRID 53120 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[S:10][CH2:11][C@H:12]([C:14]([OH:16])=[O:15])[NH2:13])([O-:3])=[O:2].[C:17](Cl)([O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[O:18]>[OH-].[Na+]>[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[S:10][CH2:11][C@H:12]([C:14]([OH:16])=[O:15])[NH:13][C:17]([O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=[O:18])([O-:3])=[O:2]

Participants

4

Reactant 2

HCID 10387Benzyl chloroformateHCID 13375100S-(o-Nitrophenyl)-D-cysteine

Product 1

HCID 13375102S-(o-Nitrophenyl)-N-carbobenzyloxy-D-cysteineYield 94.1%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent2×

Procedure

A solution of 11.60 g (48 mmol) of S-(o-nitrophenyl)-D-cysteine in 36 mL of 4N sodium hydroxide (NaOH) was cooled to 0° C. To this solution was added dropwise 6.85 mL (48 mmol) of carbobenzyloxychloride, and the mixture was stirred at room temperature for 2.5 hours. The pH was maintained at 10.8 with the addition of 4N NaOH as needed. The solution was then extracted with ether and the pH adjusted to 1.0 with 12N HCl. The resulting precipitate was dissolved in CH2Cl2, dried with Na2SO4 and evaporated to yield 17.0 g of product as a yellow gum. This material was used as is in the next reaction.

Workup

  1. extractionThe solution was then extracted with ether
  2. dissolutionThe resulting precipitate was dissolved in CH2Cl2
  3. dry with materialdried with Na2SO4
  4. customevaporated

Sources & evidence

ORD record
ord-7f09231597e846c2a476588f7ba29130
Source dataset
uspto-grants-1997_04
Patent number
US05618808

Reaction notes

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