The multicomponent condensation of an aryl aldehyde,acetyl chloride,acetonitrile,and enolizable ketone as one-pot synthesis of β-acetamido ketones in high yields was investigated using commercial,non-corrosive,and en...The multicomponent condensation of an aryl aldehyde,acetyl chloride,acetonitrile,and enolizable ketone as one-pot synthesis of β-acetamido ketones in high yields was investigated using commercial,non-corrosive,and environmentally benign Keggin and Wells-Dawson heteropolyacid catalysts.The best catalyst was H5PW10V2O40.The methodology used simple experimental conditions,and the short reaction times and high yields indicate it is a useful strategy for the large scale synthesis of β-acetamido ketones.展开更多
2-(5-Methyl-2-phenyl-4-oxazolyl)ethanol(1) was synthesized from L -aspartic acid via 5-step reactions; esterification, N -benzoylation, Dakin-West reaction, cyclizaction and reduction using LiAlH 4 in about 31 2% over...2-(5-Methyl-2-phenyl-4-oxazolyl)ethanol(1) was synthesized from L -aspartic acid via 5-step reactions; esterification, N -benzoylation, Dakin-West reaction, cyclizaction and reduction using LiAlH 4 in about 31 2% overall yield. Reacting L -aspartic acid with methanol in 0 ℃ gave 72 6% L -aspartic acid β -methyl ester hydrochloride(2), which was benzoylated to give 82 0% N -benzoyl- L -aspartic acid β -methyl ester(3). Dakin-West reaction of 3 gave 74 4% methyl 3-benzamido-4-oxovalerate(4), which was cyclized in toluene by POCl 3 to give 81 8% methyl 2-(5-methyl-2-phenyl-4-oxazolyl)acetate(5), the latter can easily convert to 1 by treatment with ether solution of LiAlH 4 in yield of 86%. All the compounds were characterized by 1H NMR, IR and elemental analysis.展开更多
A modified Dakin-West one-pot, four-component condensation of an aryl aldehyde, aryl ketone, acetyl chloride and acetonitrile in the presence of silica supported perchloric acid as an active, inexpensive, recoverable ...A modified Dakin-West one-pot, four-component condensation of an aryl aldehyde, aryl ketone, acetyl chloride and acetonitrile in the presence of silica supported perchloric acid as an active, inexpensive, recoverable and recyclable catalyst is reported for the synthesis of β-acetamido ketones under mechanical stirring and ultrasonic irradiation conditions. This system has advantages of short reaction times, good to excellent yields and the ability to carry out the large scale reactions. The use of ultrasound increases the rate of reactions compared with reactions at reflux conditions.展开更多
基金Partial financial support from the Research Council of Sabzevar Tarbiat Moallem University is greatly appreciated
文摘The multicomponent condensation of an aryl aldehyde,acetyl chloride,acetonitrile,and enolizable ketone as one-pot synthesis of β-acetamido ketones in high yields was investigated using commercial,non-corrosive,and environmentally benign Keggin and Wells-Dawson heteropolyacid catalysts.The best catalyst was H5PW10V2O40.The methodology used simple experimental conditions,and the short reaction times and high yields indicate it is a useful strategy for the large scale synthesis of β-acetamido ketones.
文摘2-(5-Methyl-2-phenyl-4-oxazolyl)ethanol(1) was synthesized from L -aspartic acid via 5-step reactions; esterification, N -benzoylation, Dakin-West reaction, cyclizaction and reduction using LiAlH 4 in about 31 2% overall yield. Reacting L -aspartic acid with methanol in 0 ℃ gave 72 6% L -aspartic acid β -methyl ester hydrochloride(2), which was benzoylated to give 82 0% N -benzoyl- L -aspartic acid β -methyl ester(3). Dakin-West reaction of 3 gave 74 4% methyl 3-benzamido-4-oxovalerate(4), which was cyclized in toluene by POCl 3 to give 81 8% methyl 2-(5-methyl-2-phenyl-4-oxazolyl)acetate(5), the latter can easily convert to 1 by treatment with ether solution of LiAlH 4 in yield of 86%. All the compounds were characterized by 1H NMR, IR and elemental analysis.
文摘A modified Dakin-West one-pot, four-component condensation of an aryl aldehyde, aryl ketone, acetyl chloride and acetonitrile in the presence of silica supported perchloric acid as an active, inexpensive, recoverable and recyclable catalyst is reported for the synthesis of β-acetamido ketones under mechanical stirring and ultrasonic irradiation conditions. This system has advantages of short reaction times, good to excellent yields and the ability to carry out the large scale reactions. The use of ultrasound increases the rate of reactions compared with reactions at reflux conditions.
