(2,2-Difluoro-1,3-benzodioxol-5-yl)-acetonitrile (1.0 eq.) was used as a raw material, mixed with 50 wt% aqueous KOH (5.0 eq.), 1-bromo-2-chloroethane (1.5 eq.) and tetrabutylammonium bromide (0.02 eq.) and heated to react for 1 hr at 70 °C. After completion of the reaction, the reaction mixture was cooled and subsequently treated with methyl tertiary butyl ether (MTBE) and water for extraction. The organic phase was washed sequentially with water and brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to afford the target product 1-(2,2-difluoro-1,3-benzodioxol-5-yl)cyclopropanecarbonitrile.
[1] Patent: WO2009/73757, 2009, A1. Location in patent: Page/Page column 21
[2] Patent: WO2010/37066, 2010, A2. Location in patent: Page/Page column 12; 26
[3] Patent: US2016/324788, 2016, A1. Location in patent: Paragraph 0361; 0362
[4] Patent: WO2009/76142, 2009, A2. Location in patent: Page/Page column 51
[5] Patent: US2007/244159, 2007, A1. Location in patent: Page/Page column 79