Benzyl chloroformate → (2S)-2-{[(benzyloxy)carbonyl]amino}-2-methylpentanedioic acid

To a stirred solution of α-methyl-D,L-glutamic acid (10 g, 62 mmol) in 2 N sodium hydroxide (62 mL) at 0-5° C. was added benzyl chloroformate (12.7 g, 74.4 mmol) over 30 min. After the addition was complete the reaction mixture was stirred at room temperature for 3 hours. During this time the pH was maintained at 11 by addition of 2N sodium hydroxide (33 mL). The reaction mixture was then extracted with ether (60 mL). The aqueous layer was cooled in an ice bath and then acidified with 4N hydrochloric acid (34 mL) to pH=1. The resulting mixture was extracted with ethyl acetate (3×100 mL). The combined ethyl acetate extracts were washed with brine (60 mL) and dried (MgSO4). The solvent was removed in vacuo to give 15.2 g (83%) of N-benzyloxycarbonyl-α-methylglutamic acid as an oil: 1H NMR (CDCl3) δ 8.73(m, 5H), 5.77(b, 1H), 5.09(s, 2H), 2.45-2.27(m, 4H), 2.0(s, 3H).

1. additionAfter the addition
2. extractionThe reaction mixture was then extracted with ether (60 mL)
3. temperatureThe aqueous layer was cooled in an ice bath
4. extractionThe resulting mixture was extracted with ethyl acetate (3×100 mL)
5. washThe combined ethyl acetate extracts were washed with brine (60 mL)
6. dry with materialdried (MgSO4)
7. customThe solvent was removed in vacuo

ORD record

ord-c8e4535a918b43bf82baf0383a12110b

Source dataset

uspto-grants-2008_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07459466B2