Reaktion #1771997

Reaktionsgleichung

Fmoc-norvaline

thionyl chloride

methanol

→

Fmoc-norVal-OMe

Lösungsmittel

ethylacetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe completion of the reaction (Rf=0.85)
2. 2
   EinengenThe reaction mixture was concentrated
3. 3
   workup.DISSOLUTIONthe remaining residue was dissolved in ethylacetate
4. 4
   WaschenThe organic layer was washed with several 200 ml portions of saturated sodium bicarbonate
5. 5
   SonstigeThe organic layer was dried
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated

Vorschrift

To a chilled solution of the commercially available Fmoc-norvaline (25 g, 73.75 mmol) in anhydrous methanol (469 ml) was added thionyl chloride (53.76 ml, 737.5 mmol) over one hour. TLC in ethylacetate taken an hour later confirmed the completion of the reaction (Rf=0.85). The reaction mixture was concentrated and the remaining residue was dissolved in ethylacetate. The organic layer was washed with several 200 ml portions of saturated sodium bicarbonate followed by brine. The organic layer was dried, filtered and concentrated to afford Fmoc-norVal-OMe) as a white solid (26.03 g) in quantitative yield. NMR δ ppm (CD3OD): 7.7 (m, 2H), 7.6 (m, 2H), 7.4 (m, 2H), 7.3 (m, 2H), 4.3 (m, 2H), 4.1 (m, 2H), 3.7 (s, 3H), 1.7 (m, 1H), 1.6 (m, 1H), 1.4 (m, 2H), 0.95 (t, 3H).

Quelle