1,3-Dithiane → 2-(4-Bromo-phenyl)-4-(2-[1,3]dithian-2-yl-ethyl)-5-methyl-oxazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Add a cold (−78° C.) solution of 2-(4-bromo-phenyl)-4-(2-iodo-ethyl)-5-methyl-oxazole (See Intermediate 30) (1.05 g, 2.67 mmol) in 15 mL THF to a cold (−78° C.) solution of dithiane anion [Preparation: Add n-BuLi (7.5 mL, 12 mmol, 1.6M in hexanes) to a −20° C. solution of 1,3-dithiane (1.92 g, 15.9 mmol) in 25 mL THF. Stir 20 min at −78° C. and add 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU, 4.03 g, 31.4 mmol).] Stir the reaction mixture at −78° C. for 15 min. Add water and warm to room temperature. Add dichloromethane, and separate the layers. Dry the crude organic extracts over MgSO4, filter and concentrate. Purify on silica gel 0-10% EtOAc/Hexanes to give 2-(4-bromo-phenyl)-4-(2-[1,3]dithian-2-yl-ethyl)-5-methyl-oxazole (0.672 g, 66%). MS (m/e): 384 (M+1).

Herkunft & Nachweise