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

A mixture of D-allylglycine (2.8 g, 24.3 mmol), 1M 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-703b0d39d20f4de19f60adedc704e002

Source dataset

uspto-grants-1997_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05670699