反应详情

A solution of 118.0 g of ethyl 2-chloro-5-[3-(2-ethoxycarbonyl-1-cyclopenten-1-yl)ureido]-benzoate in 800 ml of absolute 1,2-dimethoxyethane is added dropwise while stirring at 20° C. during 10 minutes to a suspension of 7.7 g of sodium hydride in 800 ml of absolute 1,2-dimethoxyethane. The reaction mixture is subsequently stirred for 1 hour. treated with 20 ml of acetic acid and evaporated to dryness under reduced pressure. The residue is dissolved in 2 l of methylene chloride and washed twice with 1 l of water. The organic phase is dried over anhydrous sodium sulphate and evaporated until crystallization occurs. The residue is treated with 1 l of n-hexane and the crystals are filtered off under suction and rinsed with n-hexane. There is obtained ethyl 2-chloro-5-(1,2,4,5,6,7-hexahydro-2,4-dioxo-3H-cyclopenta[d]pyrimidin-3-yl)-benzoate, m.p. 178°-180° C.

1. customevaporated to dryness under reduced pressure
2. dissolutionThe residue is dissolved in 2 l of methylene chloride
3. washwashed twice with 1 l of water
4. dry with materialThe organic phase is dried over anhydrous sodium sulphate
5. customevaporated until crystallization
6. additionThe residue is treated with 1 l of n-hexane
7. filtrationthe crystals are filtered off under suction
8. washrinsed with n-hexane