53473-85-1

5-Nitrobenzo[d]isothiazole (305 mg, 1.69 mmol) was added with iron powder (325 mesh, 473 mg), 5% aqueous acetic acid (12 mL) and ethyl acetate (12 mL), and the reaction was rapidly stirred for 1 hour at 65 °C. After completion of the reaction, the mixture was cooled to room temperature, diluted with water and ethyl acetate and filtered through diatomaceous earth. The organic layer was separated and the aqueous layer was extracted with additional ethyl acetate. The organic extracts were combined, washed with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 1,2-benzisothiazol-5-amine as a yellow solid (220 mg, 85% yield).Mass spectral data for 1,2-benzisothiazol-5-amine: m/z MS (ESI): 151 ([M + H]+).

[1] Patent: WO2007/39563, 2007, A1. Location in patent: Page/Page column 17
[2] Patent: US2007/112019, 2007, A1. Location in patent: Page/Page column 9/1
[3] Patent: WO2017/218960, 2017, A1. Location in patent: Paragraph 00425