1-methyl-4-ethyl 2-bromosuccinate | 136880-45-0

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: 1-methyl-4-ethyl 2-bromosuccinate
• 英文别名: 4-O-ethyl 1-O-methyl 2-bromobutanedioate
• CAS: 136880-45-0
• 化学式: C₇H₁₁BrO₄
• 分子量: 239.066
• InChiKey: PONPUPOFTZQQRX-UHFFFAOYSA-N

物化性质

• 沸点：
  236.8±20.0 °C(Predicted)
• 密度：
  1.452±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  1.1
• 重原子数：
  12
• 可旋转键数：
  6
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.71
• 拓扑面积：
  52.6
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  (E)-2-Bromo-but-2-enedioic acid 4-ethyl ester 1-methyl ester 在 potassium diazodicarboxylate 、 溶剂黄146 作用下， 以 甲醇 为溶剂， 反应 2.0h， 以19%的产率得到1-methyl-4-ethyl 2-bromosuccinate
  参考文献：
  名称：

  Behaviour of isomeric methyl ethyl and ethyl methyl halosuccinates under electron impact. Elimination of a halogen atom by a multi-step mechanism

  摘要：

  AbstractThe electron impact mass spectra of isomeric methyl ethyl and ethyl methyl halosuccinates (X = Cl and Br) are surprisingly different. Only the isomers with the ethyl group remote from the halogen give rise to [M ‐ X]+ ions. A low‐energy collision‐induced dissociation study of deuterium‐labelled analogues of the former isomers indicates that the [M ‐ X]+ ions are mixtures of protonated methyl ethyl maleate (major component, > 85%) and fumarate, and the loss of the halogen atom is a multi‐step process including at least two specific hydrogen transfers. Migration of a β‐hydrogen atom to the carbonyl oxygen within the ethoxycarbouyl group produces a primary radical site in a distonic intermediate which, by subsequent abstraction of a hydrogen atom from C(3), triggers the ejection of X from C(2) with concomitant double bond formation. Whereas in the other isomer an [M ‐ X]+ ion is absent or negligible, a characteristic double loss of C2H4 and CO2 is observed.

  DOI：

  10.1002/oms.1210260917

文献信息

• Bromination and iodination of donor–acceptor cyclopropanes. Evidence for an ET mechanism
  作者：Vincenzo Piccialli、M.Liliana Graziano、M.Rosaria Iesce、Flavio Cermola

  DOI：10.1016/s0040-4039(02)01966-4

  日期：2002.11

  presence of pyridine, NBS, trimethyl phosphate, and iodination with ICl and ICl/pyridine has been also performed. A common SET mechanism may be proposed for both halogenations; depending on the reaction conditions, bromination can also occur via acid-catalysed or SE2 routes. The reaction of the 2-ethoxyanalogues cis-12 and trans-12 with the same halogens proceeds in a similar manner, giving 3-formyl-2-haloesters

  2,2-二甲氧基环丙烷甲酸乙酯1a – d容易与Br 2和I 2在CCl 4或CH 2 Cl 2中反应，高产率地分别生成1-乙基-4-甲基2-卤代丁二酸酯2和3。还已经在吡啶，NBS，磷酸三甲酯存在下进行溴化，并用ICl和ICl /吡啶进行碘化。对于两种卤化，可以提出通用的SET机制。取决于反应条件，也可以通过酸催化的或S发生溴化ë 2个路由。2- ethoxyanalogues的反应顺- 12和反式- 12用相同的卤素前进以类似的方式，得到3-甲酰基-2-卤代酯与相应的diethylacetals作为主要产物一起。还研究了用催化体系NaI / m -CPBA / 18-crown-6对12的碘化。
• Behaviour of isomeric methyl ethyl and ethyl methyl halosuccinates under electron impact. Elimination of a halogen atom by a multi-step mechanism
  作者：D. Bornstein、A. Mandelbaum、I. Vidavsky、B. Domon、D. Mueller、W. J. Richter

  DOI：10.1002/oms.1210260917

  日期：1991.9

  AbstractThe electron impact mass spectra of isomeric methyl ethyl and ethyl methyl halosuccinates (X = Cl and Br) are surprisingly different. Only the isomers with the ethyl group remote from the halogen give rise to [M ‐ X]+ ions. A low‐energy collision‐induced dissociation study of deuterium‐labelled analogues of the former isomers indicates that the [M ‐ X]+ ions are mixtures of protonated methyl ethyl maleate (major component, > 85%) and fumarate, and the loss of the halogen atom is a multi‐step process including at least two specific hydrogen transfers. Migration of a β‐hydrogen atom to the carbonyl oxygen within the ethoxycarbouyl group produces a primary radical site in a distonic intermediate which, by subsequent abstraction of a hydrogen atom from C(3), triggers the ejection of X from C(2) with concomitant double bond formation. Whereas in the other isomer an [M ‐ X]+ ion is absent or negligible, a characteristic double loss of C2H4 and CO2 is observed.