反应详情

2.00 g of 6-(3-chloro-4-hydroxyphenyl)-4,5-dihydro-5-methyl-1,2,4-triazin-3(2H)-one [prepared as described in Example 2(a)] were added, whilst ice-cooling, to a stirred suspension of 364 mg of sodium hydride (as a 55% w/w dispersion in mineral oil) in 30 ml of anhydrous dimethylformamide. The mixture was then stirred at room temperature for 30 minutes, after which 0.89 ml of ethyl chloroacetate was added, and the mixture was stirred at 105°-110° C. (bath temperature) for 1.5 hours. The dimethylformamide used as the solvent was removed by evaporation under reduced pressure, and water and ethyl acetate were added to the resulting residue. The crystals which precipitated were collected by filtration, washed with ethyl acetate and dried to give the title compound as a pale yellowish-brown powder melting at 187°-189° C. (with decomposition). The ethyl acetate layer of the filtrate was separated, washed with a saturated aqueous solution of sodium chloride, dried and concentrated by evaporation under reduced pressure to give crystals, which were collected by filtration, washed with ethyl acetate and dried to give more of the title compound. The total yield was 2.11 g.

1. stirringthe mixture was stirred at 105°-110° C. (bath temperature) for 1.5 hours
2. customwas removed by evaporation under reduced pressure, and water and ethyl acetate
3. additionwere added to the resulting residue
4. customThe crystals which precipitated
5. filtrationwere collected by filtration
6. washwashed with ethyl acetate
7. customdried