Dicyclohexylcarbodiimide → Methyl 3-phenylpropionate

A solution of 2.85 g of (S)-4-carboxymethyl)alpha-[[(1,1-dimethylethoxy)carbonyl]amino]benzenepropanoic acid methyl ester in 12 mL of t-butyl alcohol was treated with 2.06 g of dicyclohexylcarbodiimide followed by 0.013 g of 4-pyrrolidinopyridine. A white precipitate formed after a few minutes and the reaction mixture was allowed to stir for 18 hours. The mixture was filtered, and the solid washed with ether. The other extracts and the filtrate were combined and washed with 1N hydrochloric acid, water, and saturated sodium bicarbonate solution and were dried over magnesium sulfate. The residue obtained after filtration and evaporation was chromatographed over 150 g of silica gel, eluting with 20% ethyl acetate-hexane to afford 1.613 g of (S)-alpha-[[(1,1-dimethylethoxy)carbonyl]amino]-4-]2-(1,1-dimethylethoxy) -2oxoethyl]benzenepropanoic acid methyl ester as a colorless oil, [α]D +6.07 (ethanol).

1. customA white precipitate formed after a few minutes
2. filtrationThe mixture was filtered
3. washthe solid washed with ether
4. washwashed with 1N hydrochloric acid, water, and saturated sodium bicarbonate solution
5. dry with materialwere dried over magnesium sulfate
6. customThe residue obtained
7. filtrationafter filtration and evaporation
8. customwas chromatographed over 150 g of silica gel
9. washeluting with 20% ethyl acetate-hexane

ORD record

ord-b41b4c7c272b428e884850eeffbbebc6

Source dataset

uspto-grants-1996_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05508437