N-bromobutanimide → 4-(Bromomethyl)-5-methyl-1,3-dioxol-2-one

Participants

Reaction Conditions

Reaction Steps

4,5-dimethyl-2-oxo-1,3-dioxole (5 g, 43.82 mmol), NBS (8.19 g, 46.01 mmol), and benzoyl peroxide (20 mg) were dissolved in CCl4 (30 mL) and heated to 80° C. for 1.5 h. The reaction mixture was cooled to r.t and the solid was filtered off. The filtrate was concentrated. The residue was purified by silica gel column to give 8.29 g of 4-bromomethyl-5-methyl-2-oxo-1,3-dioxole as a yellow oil. TEA (12 mL, 86.1 mmol) was added dropwise to a solution of 4-bromomethyl-5-methyl-2-oxo-1,3-dioxole (6 g, 31.09 mmol) and formic acid (3.36 mL) in CH3CN (96 mL) while keeping the temperature under 20° C. The mixture was stirred at r.t. for 2 h and concentrated. The product was partitioned between H2O and EtOAc (3×). The organic layer was dried with Na2SO4, concentrated and dried in vacuo to give crude formate. The resulting formate was dissolved in MeOH (40 mL) and 0.5 mL of concentrated HCl was added. The mixture was stirred at r.t. for 5 h, concentrated, and co-evaporated with toluene. The crude product was purified by silica gel column to give 2.8 g of 4-hydroxymethyl-5-methyl-2-oxo-1,3-dioxole in 69% yield. 1H NMR (300 MHz, CDCl3): d 4.40 (s, 2H), 2.60 (broad, s, 1H), 2.20 (s, 3H).

Provenance & Evidence