Ammonium Chloride → N-benzyloxycarbonyl-S-(2-aminophenyl)cysteine

HRID 1632770Notes

Reaction equation

HRID 1632770 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:24]([OH:26])=[O:25])[NH:13][C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])([O-])=O.[Cl-].[NH4+]>[Zn].CO>[NH2:1][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[S:10][CH2:11][C@@H:12]([C:24]([OH:26])=[O:25])[NH:13][C:14]([O:16][CH2:17][C:18]1[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=1)=[O:15]

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 57023645HCID 57023645, compound

Product 1

HCID 57289832N-benzyloxycarbonyl-S-(2-aminophenyl)cysteine

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 887MethanolSolvent

Procedure

A 5 l 3-neck flask fitted with a mechanical stirrer and condenser is charged with 62.1 g of S-(o-nitrophenyl)-N-carbobenzyloxy-L-cysteine, 17.6 g of ammonium chloride and 3 l of methanol. To this mixture is added 150 g of zinc dust. The reaction is heated for 4 hr at reflux and then stirred overnight at room temperature. The reaction is filtered through celite and the solids are further washed with 300 ml of boiling methanol. The methanol fractions are combined and concentrated. The residue is dissolved in 1200 ml of 1N hydrochloric acid and filtered through celite. The acidic solution is cooled to 0° C. and the pH is adjusted to 5 with saturated sodium acetate. The resulting white precipitate is collected and dried at 80° C. in vacuo to give S-(o-aminophenyl)-N-carbobenzyloxy-L-cysteine; m.p. 161°-162° C.; [α]D =-50° ((c=1.0, absolute ethanol).

Workup

  1. customA 5 l 3-neck flask fitted with a mechanical stirrer and condenser
  2. temperatureThe reaction is heated for 4 hr
  3. temperatureat reflux
  4. filtrationThe reaction is filtered through celite
  5. washthe solids are further washed with 300 ml of boiling methanol
  6. concentrationconcentrated
  7. dissolutionThe residue is dissolved in 1200 ml of 1N hydrochloric acid
  8. filtrationfiltered through celite
  9. temperatureThe acidic solution is cooled to 0° C.
  10. customThe resulting white precipitate is collected
  11. customdried at 80° C. in vacuo

Sources & evidence

ORD record
ord-9c089eee031c4e70af1250d84c18bb00
Source dataset
uspto-grants-1984_10
Patent number
US04477464

Reaction notes

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