tert-Butanol → N-(tert-Butoxycarbonyl)-3-sulfanyl-L-valine

HRID 986199Notes

Reaction equation

HRID 986199 reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[C:3]([SH:6])([CH3:5])[CH3:4].[OH-].[Na+].C(O)(C)(C)C.[C:17]([O:21][C:22](=O)[O:23]C(C)(C)C)([CH3:20])([CH3:19])[CH3:18]>O>[C:22]([NH:1][C@H:2]([C:7]([OH:9])=[O:8])[C:3]([SH:6])([CH3:5])[CH3:4])([O:21][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:23]

Participants

6

Reactant 4

HCID 6386tert-ButanolHCID 14798Sodium HydroxideHCID 92863L-PenicillamineHCID 10219638Carbonic acid, bis(1,1-dimethylethyl) ester

Product 1

HCID 14031165N-(tert-Butoxycarbonyl)-3-sulfanyl-L-valineYield 96%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

5.0 G of L-penicillamine (33.6 mmol) was dissolved in 5 ml of water containing 1.3 g of sodium hydroxide (33.6 mmol, 1 eq.). To this was added 10 ml of tert.-butanol. 8.0 G of di-tert.-butylcarbonate (37 mmol, 1.1 eq.) was added dropwise over 30 minutes. The reaction was allowed to proceed at room temperature for 6 hours. The turbid reaction mixture was diluted with 50 ml of water and extracted with hexane (3×50 ml), acidified to pH 3 with solid sodium bisulfate and extracted with ethyl acetate (3×50 ml). The combined ethyl acetate extracts were dried over sodium sulfate and, then, evaporated to dryness, yielding 8.0 g of Boc-L-penicillamine (96%): nmr (CDCl3) 1.45 ppm and 1.57 ppm, over-lapping singlets, t-butyl and beta-dimethyl protons, 4.32 ppm, br. doublet, alpha proton.

Workup

  1. customThe turbid reaction mixture
  2. extractionextracted with hexane (3×50 ml)
  3. extractionextracted with ethyl acetate (3×50 ml)
  4. dry with materialThe combined ethyl acetate extracts were dried over sodium sulfate
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-05691c47015b4f268c337d1b0c9ea5c9
Source dataset
uspto-grants-1987_12
Patent number
US04711877

Reaction notes

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