Methyl iodide → methyl 2-(3-azidopropyl)-5-(2,5-difluorophenyl)-2-phenyl-1,3,4-thiadiazole-3(2H)-carbimidothioate

To a solution of 2-(3-azidopropyl)-5-(2,5-difluorophenyl)-2-phenyl-1,3,4-thiadiazole-3(2H)-carbothioamide (0.120 g, 0.29 mmol) in 2 mL of a 4:1 mixture of DCM:MeOH was added methyl iodide (0.022 mL, 0.34 mmol). After stirring for 16 hours at room temperature, methyl iodide (0.050 mL) was added and the mixture stirred for a further 4 hours then concentrated in vacuo. The residue was partitioned between saturated NaHCO3 (10 mL) and EtOAc (10 mL) and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic phases were washed with brine (10 mL), dried over Na2SO4 and concentrated in vacuo. The residue was purified by flash column chromatography (10-20% ethyl acetate/hexanes) to afford the desired product, 0.124 g, 59%.