反应详情

To a stirred and cooled (0° C.) mixture of 9 parts of 4-[1-(1H-imidazol-1-yl)-2-methylpropyl]-1,2-benzenediamine in 80 parts of acetic acid and 20 parts of water were added 5 parts of 2-oxopentanoic acid. The reaction mixture was stirred for 12 hours at room temperature. The whole was poured into ice water and neutralized with a sodium hydroxide solution 3N. The product was extracted three times with 130 parts of dichloromethane. The combined extracts were dried, filtered and evaporated. For obtaining 6-[1-(1H-imidazol-1yl)-2-methylpropyl]-3-propyl-2(1H)-quinoxalinone, the residue was purified by column chromatography (HPLC) over silica gel using a mixture of dichloromethane and methanol (98:2 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2-butanone and 1,1'-oxybisethane. The precipitated product was filtered off and stirred in cold 4-methyl-2-pentanone. After filtration, the product was recrystallized from a mixture of methanol and 2-propanone, yielding 1.6 parts (13.2%) of the above product; mp. 259.7° C. (comp. 100).

1. temperaturecooled
2. stirringThe reaction mixture was stirred for 12 hours at room temperature
3. extractionThe product was extracted three times with 130 parts of dichloromethane
4. customThe combined extracts were dried
5. filtrationfiltered
6. customevaporated