HCID 13877862, compound → HCID 13877868, compound

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence