L-Alanine → N-((1,1-Dimethylethoxy)carbonyl)-L-alanyl-L-alanine

Beteiligte Stoffe

Reaktionsschritte

L-Alanine (3.57 g, 40 mmol) was dissolved in 18.8 ml of Triton B (40 mmol), evaporated to dryness, and the oily residue re-evaporated twice with DMF (30 ml each). The salt obtained was stirred with 11.45 g of Boc-Ala-OSu (40 mmol) in 40 ml DMF, with 4 ml of NMM added, for 20 hours. The solvent was removed and the residue taken up in 10% HOAc (100 ml). The product was extracted into EtOAc (4 times 100 ml), washed twice with a small volume of H2O, dried over Na2SO4, evaporated to a small volume, and treated with petroleum ether until cloudiness developed. A crystalline product formed on storage in the refrigerator overnight: Yield, 8.2 g (76.3%); mp 115°-118°.

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