Réaction #1771997

Équation de réaction

Fmoc-norvaline

thionyl chloride

methanol

→

Fmoc-norVal-OMe

Solvants

ethylacetate

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source