反应详情

A solution of 2,6-dichloro-α-(4-chlorophenyl)-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)benzeneacetyl chloride (0.188 mol) in 1,4-dioxane (900 ml) was stirred at RT. NaBH4 (36.25 g) was added portionwise over 2.5 hours. The resulting reaction mixture was stirred for 3 hours at RT. The reaction mixture was cooled and acidified till pH 6 with 1 N HCl. The precipitated salts were removed by filtration. The filtrate was washed with water, and the precipitate was filtered off, stirred in DIPE, filtered off and dried, yielding 22.5 g of (±)-2-[3,5-dichloro-4-[1-(4-chlorophenyl)-2-hydroxyethyl]phenyl]-1,2,4-triazine-3,5(2H,4H)-dione (comp. 420). The biphasic filtrate was separated into its layers. The organic layer was dried, filtered and the solvent was evaporated. The residue was purified by HPLC over silica gel (eluent: CH2Cl2/CH3OH 98.5/1.5 and 97/3). The pure fractions were collected and the solvent was evaporated. The residue was stirred in DIPE, filtered off, washed, and dried, yielding 24 g of (±)-2-[3,5-dichloro-4-[1-(4-chlorophenyl)-2-hydroxyethyl]phenyl]-1,2,4-triazin-3,5(2H,4H)-dione (comp. 420).

1. customThe resulting reaction mixture
2. temperatureThe reaction mixture was cooled
3. customThe precipitated salts were removed by filtration
4. washThe filtrate was washed with water
5. filtrationthe precipitate was filtered off
6. stirringstirred in DIPE
7. filtrationfiltered off
8. customdried