Phosphorus oxychloride → HCID 19973430, compound

Participants

Reaction Steps

A solution of 5-(2-fluoro-5-methoxyphenyl)-pyrazin-2-one in POCl3 was heated at 100° C.-110° C. in a sealed tube for 16 h. After evaporating the remaining POCl3 under reduced pressure, the brown residue was taken up in EtOAc and washed (3×) with saturated aqueous NaHCO3 solution. The EtOAc solution was then dried (Na2SO4) and concentrated under reduced pressure leaving a brown oil. The oil was filtered through a pad of silica gel (30% EtOAc/hexanes eluent) and the solvents were again evaporated under reduced pressure. The oil was taken up in CH2Cl2, heated for 5 min. with decolorizing charcoal and filtered through celite. Evaporation of the solvent afforded 2-chloro-5-(2-fluoro-5-methoxyphenyl) pyrazine as a light-brown oil.

Provenance & Evidence