Phosphorus oxychloride → Methyl 4-(3-chloro-1,2,4-triazin-6-yl)benzoate

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Reaction Conditions

Reaction Steps

A mixture of methyl 4-(3-oxo-2,3-dihydro-1,2,4-triazin-6-yl)benzoate (13.4 g, 0.0580 mol), phosphoryl chloride (30 mL, 0.3 mol) in chloroform (50 mL) was refluxed (oil-bath temperature about 100° C.) for 2 h. After cooling to RT, the mixture was concentrated to remove excess phosphoryl chloride. The residue was dissolved in methylene chloride and poured into ice-water, and carefully neutralized with K2CO3. The organic layer was separated and the aqueous solution was extracted with methylene chloride. The combined organic phases were dried over Na2SO4, concentrated, and further purified by chromatography to afford the desired product (2.5 g, 17%). LCMS: (M+H)=249.9. 1H NMR (300 MHz, CDCl3): in ppm, 3.98 (s, 3H), 8.18 (d, 2H), 8.24 (d, 2H), 8.96 (s, 1H).

Provenance & Evidence