HCID 13877862, compound → HCID 13877868, compound

HRID 256078Notes

Reaction equation

HRID 256078 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:22]([OH:24])=[O:23])[CH2:10][S:11][CH:12]([C:17]1[S:18][CH:19]=[CH:20][CH:21]=1)[CH2:13][N+:14]([O-])=O)=[O:7])([CH3:4])([CH3:3])[CH3:2].[H][H]>C(O)(=O)C.[Pd]>[NH2:14][CH2:13][CH:12]([S:11][CH2:10][C@@H:9]([C:22]([OH:24])=[O:23])[NH:8][C:6]([O:5][C:1]([CH3:2])([CH3:3])[CH3:4])=[O:7])[C:17]1[S:18][CH:19]=[CH:20][CH:21]=1

Participants

5

Reactant 2

HCID 13877862HCID 13877862, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 13877868HCID 13877868, compoundYield 81.8%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
70 °C

Procedure

129 g of N-t-butoxycarbonyl-S-[2-nitro-1-(2-thienyl)ethyl]-L-cysteine [produced as described in step (a) above] were dissolved in 1 liter of acetic acid. To the solution were added 100 g of 10% w/w palladium-on-carbon, and the mixture was shaken for 5 hours at 70° C. in an atmosphere containing hydrogen at a partial pressure of 3-4 kg/cm2. The palladium-on-carbon catalyst was then filtered off, and the filtrate was condensed by evaporation under reduced pressure. The remaining acetic acid was then distilled off as an azeotrope with toluene. The residue was dissolved in a mixture of 500 ml of ethyl acetate and 100 ml of water, and the pH of the aqueous layer was adjusted to a value of 6.1, by adding sodium bicarbonate powder, whilst stirring. The organic layer was then separated, and the aqueous layer was extracted with a mixture of ethyl acetate and methylene chloride. The separated organic layer and the extract were combined and the mixture was dried over anhydrous magnesium sulfate, after which the solvent was distilled off. The gummy residue was solidified by the addition of diethyl ether and then recovered by filtration, giving 97.1 g of the title compound as a powder. This compound was used in the reaction of step (c) without any further purification.

Workup

  1. filtrationThe palladium-on-carbon catalyst was then filtered off
  2. customcondensed
  3. customby evaporation under reduced pressure
  4. distillationThe remaining acetic acid was then distilled off as an azeotrope with toluene
  5. dissolutionThe residue was dissolved in a mixture of 500 ml of ethyl acetate and 100 ml of water
  6. additionby adding sodium bicarbonate powder
  7. stirringwhilst stirring
  8. customThe organic layer was then separated
  9. extractionthe aqueous layer was extracted with a mixture of ethyl acetate and methylene chloride
  10. dry with materialthe mixture was dried over anhydrous magnesium sulfate
  11. distillationafter which the solvent was distilled off
  12. additionThe gummy residue was solidified by the addition of diethyl ether
  13. filtrationrecovered by filtration

Sources & evidence

ORD record
ord-f555aa980c7b440382bc337355f3a673
Source dataset
uspto-grants-1987_10
Patent number
US04699905

Reaction notes

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