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

To a mixture of 3.0 g (16.9 mmol) of β-thienyl-D,L-alanine in 75 mL of water and 60 mL of dioxane, was added 5.6 g (40.6 mmol) of anhydrous potassium carbonate, followed by 2.85 mL (20 mmol) of carbobenzyloxychloride. The resulting mixture was stirred rapidly for approximately one hour. When the reaction was substantially complete, as indicated by thin layer chromatography (21/7/7/9, ethyl acetate/acetic acid/acetonitrile/water), the reaction mixture was concentrated. The resultant layers were separated and the aqueous layer was washed with 75 mL of diethyl ether and then layered with 150 mL of methylene chloride. The resultant mixture was acidified with rapid stirring to pH=2.0 using 5N hydrochloric acid. The layers were then separated, and the organic layer was dried sodium sulfate (Na2SO4), filtered and concentrated to provide 5.05 g of desired compound (98%).

1. concentrationthe reaction mixture was concentrated
2. customThe resultant layers were separated
3. washthe aqueous layer was washed with 75 mL of diethyl ether
4. stirringwith rapid stirring to pH=2.0
5. customThe layers were then separated
6. filtrationfiltered
7. concentrationconcentrated

ORD record

ord-c7f3fc7a4e744d51ba5908cef44464ab

Source dataset

uspto-grants-1996_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05480887