4-(bromomethyl)benzo[d][1,3]dioxole

Synthesis

General procedure: An ethyl ether solution of phosphorus tribromide is prepared by dissolving 3.1 ml (0.033 mol) of phosphorus tribromide in 15 ml of ether. This solution was slowly added dropwise to an ether solution containing 4.5 g (0.03 mol) of 1,3-benzodioxolane-4-alkylmethanol at 0°C in an ice bath. After the dropwise addition was completed, the reaction was continued with stirring at 0°C for 3 hours. Upon completion of the reaction, the reaction was quenched with saturated sodium carbonate solution, the organic phase was separated and washed with saturated sodium chloride solution. The organic phase was dried over anhydrous sodium sulfate for 8 hours and then filtered to remove the desiccant. The filtrate was distilled under reduced pressure to remove the solvent to obtain the crude product. The crude product was purified by fast silica gel column chromatography using petroleum ether: ethyl acetate (19:1) as eluent to give 5.8 g of the yellow oily target product 4-(bromomethyl)benzo[d][1,3]dioxole in 90.6% yield.

References

[1] Australian Journal of Chemistry, 1985, vol. 38, # 10, p. 1481 - 1489
[2] Patent: CN103804341, 2018, B. Location in patent: Paragraph 0064; 0072; 0073
[3] Patent: CN108690016, 2018, A. Location in patent: Paragraph 0555; 0557; 0558
[4] Patent: WO2007/44796, 2007, A2. Location in patent: Page/Page column 108-109
[5] Journal of the American Chemical Society, 1957, vol. 79, p. 6033