Dicyclohexylcarbodiimide → 3-pentanone O-{2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoyl}oxime

Beteiligte Stoffe

Reaktionsschritte

0.9 g of 3-pentanone oxime is added at room temperature to a suspension of 3.0 g of 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoic acid in 50 ml of diethyl ether. Thereafter, a solution of 1.9 g of dicyclohexylcarbodiimide and 0.1 g of 4-pyrrolidinopyridine in 15 ml of diethyl ether is added dropwise over 10 minutes. The reaction mixture is stirred at room temperature for 12 hours. Subsequently, it is filtered and evaporated to dryness under reduced pressure. The residue is purified by chromatography on silica gel with n-hexane/diethyl ether (4:1) as the eluent. In this manner there is obtained 3-pentanone O-{2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4 -trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorobenzoyl}oxime, m.p. 128°-130° C.

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