Benzyl chloroformate → 2-{[(Benzyloxy)carbonyl]amino}-3-(thiophen-2-yl)propanoic acid

HRID 342524

Reaction equation

HRID 342524 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][CH:7]([C:9]([OH:11])=[O:10])[NH2:8].C([O-])([O-])=O.[K+].[K+].[C:18](Cl)([O:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)=[O:19].CCOC(C)=O.CC(O)=O.CC#N.O>O>[CH2:21]([O:20][C:18]([NH:8][CH:7]([C:9]([OH:11])=[O:10])[CH2:6][C:2]1[S:1][CH:5]=[CH:4][CH:3]=1)=[O:19])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

6

Reactant 4

HCID 10387Benzyl chloroformateHCID 11430Potassium CarbonateHCID 914442-ThienylalanineHCID 131719237EtOAc AcOH CH3CN H2O

Product 1

HCID 128068302-{[(Benzyloxy)carbonyl]amino}-3-(thiophen-2-yl)propanoic acidYield 98%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Into a 500 ml flask was placed 3.0 g of 3-(2-Thienyl)-D,L-alanine (optically active material in the L-form is available from Aldrich or SIGMA and could be used to obtain an optically active product) in 75 ml H2O/60 ml dioxane, and 5.6 g K2CO3 was added, followed by 2.85 ml of carbobenzyloxy chloride. The mixture was stirred rapidly for 1 hour. TLC (21/7/7/9, EtOAc/AcOH/CH3CN/H2O) showed that the starting material was gone. A new higher Rf product was seen. The dioxane was concentrated off and the aqueous layer was-washed with Et2O (75 ml). The aqueous layer was mixed with CH2Cl2 (150 ml) and acidified to pH=2.0 with 5N HCl. The desired N-(Benzyloxycarbonyl)-3-(2-thienyl)-D,L-alanine was extracted with CH2Cl2. The organic layer was separated and dried with Na2So4, filtered, and concentrated to give 5.05 g of desired N-(Benzyloxycarbonyl)-3-(2-thienyl)-D,L-alanine (98% yield).

Workup

  1. customInto a 500 ml flask was placed
  2. concentrationThe dioxane was concentrated off
  3. washthe aqueous layer was-washed with Et2O (75 ml)
  4. additionThe aqueous layer was mixed with CH2Cl2 (150 ml)
  5. extractionThe desired N-(Benzyloxycarbonyl)-3-(2-thienyl)-D,L-alanine was extracted with CH2Cl2
  6. customThe organic layer was separated
  7. customdried with Na2So4
  8. filtrationfiltered
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-f106c4548bc9403089981230e9bef7dd
Source dataset
uspto-grants-1999_01
Patent number
US05859002

Linked notes

Loading…