Lawesson's reagent → 2-(5-(3-Amino-5-(trifluoromethyl)pyridin-2-yl)-1,3,4-thiadiazol-2-yl)-1,1,1-trifluoropropan-2-ol

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Reaction Steps

A mixture comprising 3-amino-N′-(3,3,3-trifluoro-2-hydroxy-2-methylpropanoyl)-5-(trifluoromethyl) picolinohydrazide (184 mg, 0.511 mmol) in toluene (5.108 ml) was treated with Lawesson reagent (310 mg, 0.766 mmol) and heated at reflux for 1 h. The reaction mixture was diluted with water and extracted with EtOAc. The combined organic extracts were washed saturated sodium bicarbonate solution, brine, dried (phase separator) and concentrated in vacuo. Purification by chromatography on silica eluting with 0-30% EtOAc in iso-hexane afforded an orange gum. Further purification was carried out by preparative reverse phase HPLC eluting with 30-70% MeCN in water (0.1% TFA) to afford the title compound; 1H NMR (400 MHz, DMSO-d6) δ 8.2 (1H, s), 8.0 (1H, s), 7.6 (1H, s), 7.4 (2H, s), 1.9 (3H, s). LC-MS Rt=4.03 min [M+H]+ 359.4 Method 10minLC_v003.

Provenance & Evidence