Citric Acid → N-(tert-butoxycarbonyl)-2-aminoethanethiol

HRID 1461470Notes

Reaction equation

HRID 1461470 reaction equation
[C:1]([O:5][C:6]([NH:8][CH2:9][CH2:10][S:11]SCCN)=[O:7])([CH3:4])([CH3:3])[CH3:2].[BH4-].[Na+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C(O)C>[C:1]([O:5][C:6]([NH:8][CH2:9][CH2:10][SH:11])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 311Citric AcidHCID 4311764Sodium borohydrideHCID 22245556tert-butyl N-(2-((2-aminoethyl)disulfanyl)ethyl)carbamate

Product 1

HCID 3017761N-(tert-butoxycarbonyl)-2-aminoethanethiolYield 106.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of bis N-(t-butyloxycarbonyl)-cystamine (77.37 g, 0.220 mole) from Example 1, in 1 L of ethanol was treated with NaBH4 (32.5 g, 0.859 mmole). Vigorous gas evolution ensued and subsided in 40 minutes. The reaction was stirred for an additional half hour and was poured into 2.5 L of a cold dilute solution of citric acid (pH 6). The mixture was then extracted with 3×1 L of chloroform. The combined organic extracts were dried with MgSO4 and the solvents were removed under reduced pressure. The resulting residue was distilled (66°-73° C. 0.25 torr) to obtain the product (41.5 g, 53% yield).

Workup

  1. extractionThe mixture was then extracted with 3×1 L of chloroform
  2. dry with materialThe combined organic extracts were dried with MgSO4
  3. customthe solvents were removed under reduced pressure
  4. distillationThe resulting residue was distilled (66°-73° C. 0.25 torr)

Sources & evidence

ORD record
ord-7311b23c74dc40e28c313817a301885f
Source dataset
uspto-grants-1991_12
Patent number
US05075440

Reaction notes

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