Nitrogen → 2-[4-(2-Methyl-[1,3]dioxolan-2-yl)-butyl]-oxazole-4-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 2-[4-(2-methyl-[1,3]dioxolan-2-yl)-butyl]-4,5-dihydro-oxazole-4-carboxylic acid methyl ester (1.04 g, 3.83 mmol) in CH2Cl2 (30 mL) at 0° C. was treated with DBU (0.72 mL, 4.79 mmol). Then, bromotrichloromethane (0.95 mL, 9.58 mmol) was added dropwise over 20 min and the reaction mixture was stirred at 0° C. for 4 h then at rt overnight. Additional DBU (0.72 mL, 4.79 mmol) and bromotrichloromethane (0.95 mL, 9.58 mmol) were added at 0° C. and the reaction mixture stirred at rt for 24 h. Sat. aq. NaHCO3 was then added and the aq. phase was extracted with CH2Cl2 (3×). The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (20:1→1:1 hept-EA) gave the title compound as a white solid. TLC: rf (1000:50:4 CH2Cl2-MeOH—NH3)=0.25. LC-MS-conditions 02: tR=0.84 min [M+H]+=270.35.

Provenance & Evidence