反应详情

A mixture of 13.2 parts of 2,6-dichloro-α-(4-chlorophenyl)-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)benzeneacetamide, 648 parts of concentrated hydrochloric acid and 200 parts of acetic acid was stirred and refluxed for 224 hours. The resulting product was filtered off, washed with water and taken up in 100 parts of water. After treatment with a sodium hydroxide solution, the resulting solution was acidified with concentrated hydrochloric acid. The product was filtered off and purified by column chromatography over silica gel using a mixture of methylbenzene, tetrahydrofuran and acetic acid (70:30:1 by volume) as eluent. The pure fractions were collected and the eluent was evaporated, yielding 3.8 parts (27.8%) of 2,6-dichloro-α-(4-chlorophenyl)-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)benzeneacetic acid; mp. 219.5° C. (intermediate 29).

1. temperaturerefluxed for 224 hours
2. filtrationThe resulting product was filtered off
3. washwashed with water
4. filtrationThe product was filtered off
5. custompurified by column chromatography over silica gel using
6. additiona mixture of methylbenzene, tetrahydrofuran and acetic acid (70:30:1 by volume) as eluent
7. customThe pure fractions were collected
8. customthe eluent was evaporated