The condensation reaction of 4-hydroxycoumarin with each of ah substituted benzalacetones in（absolute） ethanol gave coumarin analogues which were subsequently converted to their ethyl ethers（cyclocou-（marin））.Th...The condensation reaction of 4-hydroxycoumarin with each of ah substituted benzalacetones in（absolute） ethanol gave coumarin analogues which were subsequently converted to their ethyl ethers（cyclocou-（marin））.The ethers can be quantitatively converted back to the coumarin analogues by acid hydrolysis.Four of them are new substances.The reaction mechanism is discussed in detail.All the products were characterized by HPLC,IR and 1H NMR.Compared with the present process in the literature,the process for the synthesis of the coumarin analogues is obviously improved on the reaction time,temperature,solvent,（catalyst）,and post-treatment.展开更多
文摘The condensation reaction of 4-hydroxycoumarin with each of ah substituted benzalacetones in（absolute） ethanol gave coumarin analogues which were subsequently converted to their ethyl ethers（cyclocou-（marin））.The ethers can be quantitatively converted back to the coumarin analogues by acid hydrolysis.Four of them are new substances.The reaction mechanism is discussed in detail.All the products were characterized by HPLC,IR and 1H NMR.Compared with the present process in the literature,the process for the synthesis of the coumarin analogues is obviously improved on the reaction time,temperature,solvent,（catalyst）,and post-treatment.
