Convergent Domino Knoevenagel Hetero-DielsAlder and Domino Oxidation Hetero-DielsAlder Reactions Encountered in an Unexpected Formation of Novel 5-Aryl-1H-pyrano[2,3-d]pyrimidine-2,4(3H,5H)-diones and 5-Aryl-2,3-dihydro-2-thioxo-1H-pyrano[2,3-d]pyrimidi
作者:Nace Zidar、Danijel Kikelj
DOI:10.1002/hlca.201000325
日期:2011.5
Convergent domino Knoevenagel hetero‐DielsAlder and domino oxidation hetero‐DielsAlder reactions, in which both diene and dienophile are formed under the same reaction conditions in situ, are described for the first time, and their application is demonstrated by a one‐pot synthesis of novel 5‐aryl‐1H‐pyrano[2,3‐d]pyrimidine‐2,4(3H,5H)‐diones and 5‐aryl‐2,3‐dihydro‐2‐thioxo‐1H‐pyrano[2,3‐d]pyrimidin‐4(5H)‐ones
会聚多米诺的Knoevenagel杂狄尔斯阿尔德和多米诺氧化杂狄尔斯阿尔德反应,其中两个二烯和亲双烯体在相同的反应条件下形成原位,被首次描述,并通过一维它们的应用表明一锅法合成新的5-芳基- 1 H ^ -吡喃并[2,3- d ]嘧啶-2,4(3 ħ,5 ħ) -二酮和5-芳基-2,3-二氢-2-硫代-1- ħ -pyrano [2,3 - d ]嘧啶-4(5 H)-ones。
Preparation of 5-substituted benzylbarburituric acids and investigation of the effect of the benzyl and substituted benzyl groups on the acidity of barbituric acid
作者:John V. Tate、William N. Tinnerman、Vito Jurevics、Harold Jeskey、Edward R. Biehl
DOI:10.1002/jhet.5570230103
日期:1986.1
5-substituted benzylbarbituric acids has been determined in 50% ethanol/water and they were found to be more acidic than barbituric acid. The pKas of these derivatives obey Hammett's equation indicating that their acidity is affected by substituents in the same manner as the benzoic acid ionization constants. A synthesis of these acids is described.
已在50%的乙醇/水中测定了5-苄基巴比妥酸和一系列5-取代的苄基巴比妥酸的酸度,发现它们比巴比妥酸更酸性。这些衍生物的p K a s服从哈米特方程,表明它们的酸度受取代基影响的方式与苯甲酸电离常数相同。描述了这些酸的合成。
JOVANOVIC M. V.; BIEHL E. R., HETEROCYCLES, 24,(1986) N 11, 3129-3141