Benzyl chloroformate → (R)-2-(((Benzyloxy)carbonyl)amino)pent-4-enoic acid

A mixture of D-allylglycine (2.8 g, 24.3 mmol), 1 M aqueous sodium hydroxide solution (25 ml), and tetrahydrofuran (10 ml, distilled from ketyl) was stirred at room temperature until homogeneous then cooled in an ice-bath. To the resulting rapidly stirred solution was added about 5 mL of 1.0M aqueous sodium hydroxide solution then dropwise about 1 g of benzyl chloroformate. This was repeated 4 additional times until a total of 28 mL of 1.0M aqueous sodium hydroxide solution and 4.80 g (95%, 27 mmol) of benzyl chloroformate were added. The reaction mixture was stirred for 15 minutes at 0° C. then 30 minutes at room temperature and then extracted with 50 mL of ether. The aqueous layer was acidified (pH=1.5) the by addition of 6N hydrochloric acid solution (about 10 mL) then extracted with three-50 mL portions of ether. The three ether extracts were combined, dried (magnesium sulfate) and concentrated in vacuo to afford 6.01 g of title product as a colorless oil.

1. temperaturethen cooled in an ice-bath
2. additionwere added
3. stirringThe reaction mixture was stirred for 15 minutes at 0° C.
4. extraction30 minutes at room temperature and then extracted with 50 mL of ether
5. additionby addition of 6N hydrochloric acid solution (about 10 mL)
6. extractionthen extracted with three-50 mL portions of ether
7. dry with materialdried (magnesium sulfate)
8. concentrationconcentrated in vacuo

ORD record

ord-036c2646284f44fbbd5b2e1f26ee278f

Source dataset

uspto-grants-1996_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05508272