Methyl iodide → 2-chloro-5-fluorobenzyl-6-methyl-3-(methylthio)-1,2,4-triazin-5(4H)-one

Participants

Reaction Steps

To a suspension of 4-(2-chloro-5-fluorobenzyl)-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one (29, 3.06 g, 10.72 mmol) in ethanol (50 mL) was added MeI (2.44 g, 17.1 mmol) followed by NaOH (429 mg, 10.72 mmol). The mixture was stirred at RT for 40 min to produce a clear yellow solution. The reaction was diluted with water (200 mL), and extracted with EtOAc (100 mL×3). The extracts were washed with brine, dried over MgSO4, and concentrated to give the crude product (3.195 g). This was crystallized from ethyl acetate-petroleum ether to give 4-(2-chloro-5-fluorobenzyl)-6-methyl-3-(methylthio)-1,2,4-triazin-5(4H)-one (30). MS: m/z, 300 (100%, M+1), 302 (35%).

Provenance & Evidence