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Example 301a Synthesis of 6-(trifluoromethyl)pyridazin-3-amine: a mixed solution of 3-chloro-6-trifluoromethylpyridazine (1.6 g, 8.80 mmol) and ammonium hydroxide (9 mL) in tetrahydrofuran (THF, 3 mL) was placed in a microwave reactor and reacted for 1 hour at 100 °C. After completion of the reaction, the reaction mixture was concentrated and the residue was extracted with dichloromethane. The organic phases were combined, dried with anhydrous magnesium sulfate (MgSO?), filtered and concentrated under reduced pressure to afford the target product 6-(trifluoromethyl)pyridazin-3-amine (301a, 1.3 g, 93% yield) as a white solid. Mass spectrometry (MS-ESI) analysis showed [M + H]? m/z 164.1.

[1] Patent: WO2007/48779, 2007, A1. Location in patent: Page/Page column 16
[2] Patent: EP2773638, 2015, B1. Location in patent: Paragraph 1220; 1221
[3] Patent: WO2016/51193, 2016, A1. Location in patent: Paragraph 00438; 00439; 00440