4-Chloro-2-nitrophenyl cinnamate

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 肉桂酸及其衍生物
• 英文名称: 4-Chloro-2-nitrophenyl cinnamate
• 英文别名: (4-chloro-2-nitrophenyl) (E)-3-phenylprop-2-enoate
• 化学式: C₁₅H₁₀ClNO₄
• 分子量: 303.702
• InChiKey: QOJHSHVDJUBLQZ-RMKNXTFCSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.2
• 重原子数：
  21
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  72.1
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  4-Chloro-2-nitrophenyl cinnamate 在 氢氧化钾 作用下， 以 1,4-二氧六环 、 水 为溶剂， 生成 肉桂酸 、 4-氯-2-硝基苯酚
  参考文献：
  名称：

  Participation of an Extended p-Oxo Ketene Intermediate in the Dissociative Alkaline Hydrolysis of Aryl 4-Hydroxycinnamates

  摘要：

  The alkaline hydrolysis of 4-hydroxycinnamate esters of acidic phenols follows an E1cB mechanism and involves the participation of an ''extended'' p-oxo ketene intermediate. The apparent bimolecular rate constant (k(a)K(a)/K-W) for the hydrolysis of the 2,4-dinitrophenyl ester is some 2500-fold larger than that determined from the Hammett relationship for the B(Ac)2 alkaline hydrolysis of substituted 2,4-dinitrophenyl cinnamates. The positive value of the entropy of activation for the hydrolysis of 2,4-dinitrophenyl 4'-hydroxycinnamate and trapping experiments with nitrogen nucleophiles are consistent with the dissociative pathway. A change from a E1cB to a B(Ac)2 mechanism is expected for esters with leaving groups having pK(a) higher than ca. 6.7. The higher E1cB reactivity of 2,4-dinitrophenyl 4'-hydroxycinnamate compared to that of the corresponding 4'-hydroxybenzoate is due to the vinylene group that further favors the dissociative route, probably increasing the stability of the unsaturated intermediate.

  DOI：

  10.1021/jo00100a031
• 作为产物：
  描述：

  肉桂酸 、 4-氯-2-硝基苯酚 在 吡啶 N,N'-二环己基碳二亚胺 作用下， 以 乙酸乙酯 为溶剂， 生成 4-Chloro-2-nitrophenyl cinnamate
  参考文献：
  名称：

  Participation of an Extended p-Oxo Ketene Intermediate in the Dissociative Alkaline Hydrolysis of Aryl 4-Hydroxycinnamates

  摘要：

  The alkaline hydrolysis of 4-hydroxycinnamate esters of acidic phenols follows an E1cB mechanism and involves the participation of an ''extended'' p-oxo ketene intermediate. The apparent bimolecular rate constant (k(a)K(a)/K-W) for the hydrolysis of the 2,4-dinitrophenyl ester is some 2500-fold larger than that determined from the Hammett relationship for the B(Ac)2 alkaline hydrolysis of substituted 2,4-dinitrophenyl cinnamates. The positive value of the entropy of activation for the hydrolysis of 2,4-dinitrophenyl 4'-hydroxycinnamate and trapping experiments with nitrogen nucleophiles are consistent with the dissociative pathway. A change from a E1cB to a B(Ac)2 mechanism is expected for esters with leaving groups having pK(a) higher than ca. 6.7. The higher E1cB reactivity of 2,4-dinitrophenyl 4'-hydroxycinnamate compared to that of the corresponding 4'-hydroxybenzoate is due to the vinylene group that further favors the dissociative route, probably increasing the stability of the unsaturated intermediate.

  DOI：

  10.1021/jo00100a031

文献信息

• Associative and Dissociative Pathways in the Alkaline Hydrolysis of Aryl 2-Hydroxycinnamates
  作者：Giorgio Cevasco、Sergio Thea

  DOI：10.1021/jo00106a016

  日期：1995.1

  Aryl 2-hydroxycinnamate esters hydrolyze in alkaline solutions (20% dioxane-water v/v) obeying the rate law k(obs) = k(2) + k(b)[OH-]/(1 + a(H)/K-a), where K-a is the ionization constant of the hydroxy group of the ester and kb is the second-order rate constant for the attack of hydroxide ion on the ionized ester. Kinetic data and activation parameters for the hydrolysis of the 2,4-dinitrophenyl ester show that the mechanism giving rise to the k(a) term cannot be a simple B(Ac)2 type process and suggest the occurrence of a E1cB mechanism involving an ''extended'' o-oxoketene intermediate. The Bronsted plot of the apparent second-order rate constants (k(a)K(a)/k(w)) versus the pK of the leaving group indicates that the reaction mechanism changes from E1cB to B(Ac)2 for esters with leaving groups having pK higher than about 6.
• Participation of an Extended p-Oxo Ketene Intermediate in the Dissociative Alkaline Hydrolysis of Aryl 4-Hydroxycinnamates
  作者：Giorgio Cevasco、Sergio Thea

  DOI：10.1021/jo00100a031

  日期：1994.10

  The alkaline hydrolysis of 4-hydroxycinnamate esters of acidic phenols follows an E1cB mechanism and involves the participation of an ''extended'' p-oxo ketene intermediate. The apparent bimolecular rate constant (k(a)K(a)/K-W) for the hydrolysis of the 2,4-dinitrophenyl ester is some 2500-fold larger than that determined from the Hammett relationship for the B(Ac)2 alkaline hydrolysis of substituted 2,4-dinitrophenyl cinnamates. The positive value of the entropy of activation for the hydrolysis of 2,4-dinitrophenyl 4'-hydroxycinnamate and trapping experiments with nitrogen nucleophiles are consistent with the dissociative pathway. A change from a E1cB to a B(Ac)2 mechanism is expected for esters with leaving groups having pK(a) higher than ca. 6.7. The higher E1cB reactivity of 2,4-dinitrophenyl 4'-hydroxycinnamate compared to that of the corresponding 4'-hydroxybenzoate is due to the vinylene group that further favors the dissociative route, probably increasing the stability of the unsaturated intermediate.