diethyl 2-allyl-3-benzothiophenemalonate | 149682-20-2

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 苯并噻吩类
• 英文名称: diethyl 2-allyl-3-benzothiophenemalonate
• 英文别名: Diethyl 2-(2-prop-2-enyl-1-benzothiophen-3-yl)propanedioate
• CAS: 149682-20-2
• 化学式: C₁₈H₂₀O₄S
• 分子量: 332.42
• InChiKey: YDUQZTZVUZUSNA-UHFFFAOYSA-N

物化性质

• 沸点：
  427.3±40.0 °C(Predicted)
• 密度：
  1.185±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  4.7
• 重原子数：
  23
• 可旋转键数：
  9
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  80.8
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  diethyl 2-allyl-3-benzothiophenemalonate 反应 8.0h， 以26%的产率得到trans-ethyl 2,3-dihydro-1-(ethoxycarbonyl)-1H-benzocyclopentathiophene-2-acetate
  参考文献：
  名称：

  Cope rearrangements in the benzo[b]thiophene series

  摘要：

  The inability to observe Cope rearrangement products at elevated temperatures for diethyl alpha-allyl-2-naphthalenemalonate (1) and diethyl alpha-allyl-9-phenanthrenemalonate (2) does not extend to the analogous systems resulting from replacement of the aromatic units by 2- and 3-benzo[b]thiophene nuclei. Thermal rearrangement of diethyl alpha-allyl-3-benzo[b]thiophenemalonate (5) at 215-255-degrees-C for 11 h produces the expected Cope rearrangement product diethyl 2-allyl-3-benzo[b]thiophenemalonate (10) (8%) accompanied by trans- and cis-ethyl 2,3-dihydro-1-(ethoxycarbonyl)-1H-benzo-[b]cyclopenta[d]thiophene-2-acetate (9a) (10%) and (9b) (5%), respectively. The structure elucidation of 10, 9a, and 9b was done by spectroscopy. The attempted structure verification of 10 by an independent route gave diethyl 2-(1-propenyl)-3-benzo[b]thiophenemalonate (12) which when heated at 230-240-degrees-C for 18 h gave 1-carbethoxy-2-hydroxy-3-methyldibenzothiophene (16) as a major product. Similar results were observed with 2-substituted analogues of 5, both diethyl 3-allyl-2-benzo[b]thiophenemalonate (24) and ethyl 1,2-dihydro-3-(ethoxycarbonyl)-3H-benzo[b]cyclopenta-[d]thiophene-2-acetate (25) being formed. In this case the structure of 24 was verified by synthesis. An extension of this involved a study of thermal rearrangement of analogous compound ethyl alpha-allyl-alpha-cyano-3-benzo[b]thiopheneacetate (30). Thermal rearrangement of 30 at 235-245-degrees-C for 8 h gave the expected Cope rearrangement product ethyl alpha-cyano-2-allyl-3-benzo[b]thiopheneacetate (32) (6%) along with an unexpected diastereomeric mixture of 1-cyano-1-(ethoxycarbonyl)-2-methyl-2,3-dihydro-1H-benzo[b]cyclopenta[d]thiophenes(33)(18%). Speculative mechanistic considerations are offered regarding the mode of transformation of 12 to 16 and 32 to 33.

  DOI：

  10.1021/jo00068a034
• 作为产物：
  描述：

  3-碘苯并[b]噻吩 在 sodium ethanolate 、 sodium hydride 、 copper(I) bromide 作用下， 生成 diethyl 2-allyl-3-benzothiophenemalonate
  参考文献：
  名称：

  Cope rearrangements in the benzo[b]thiophene series

  摘要：

  The inability to observe Cope rearrangement products at elevated temperatures for diethyl alpha-allyl-2-naphthalenemalonate (1) and diethyl alpha-allyl-9-phenanthrenemalonate (2) does not extend to the analogous systems resulting from replacement of the aromatic units by 2- and 3-benzo[b]thiophene nuclei. Thermal rearrangement of diethyl alpha-allyl-3-benzo[b]thiophenemalonate (5) at 215-255-degrees-C for 11 h produces the expected Cope rearrangement product diethyl 2-allyl-3-benzo[b]thiophenemalonate (10) (8%) accompanied by trans- and cis-ethyl 2,3-dihydro-1-(ethoxycarbonyl)-1H-benzo-[b]cyclopenta[d]thiophene-2-acetate (9a) (10%) and (9b) (5%), respectively. The structure elucidation of 10, 9a, and 9b was done by spectroscopy. The attempted structure verification of 10 by an independent route gave diethyl 2-(1-propenyl)-3-benzo[b]thiophenemalonate (12) which when heated at 230-240-degrees-C for 18 h gave 1-carbethoxy-2-hydroxy-3-methyldibenzothiophene (16) as a major product. Similar results were observed with 2-substituted analogues of 5, both diethyl 3-allyl-2-benzo[b]thiophenemalonate (24) and ethyl 1,2-dihydro-3-(ethoxycarbonyl)-3H-benzo[b]cyclopenta-[d]thiophene-2-acetate (25) being formed. In this case the structure of 24 was verified by synthesis. An extension of this involved a study of thermal rearrangement of analogous compound ethyl alpha-allyl-alpha-cyano-3-benzo[b]thiopheneacetate (30). Thermal rearrangement of 30 at 235-245-degrees-C for 8 h gave the expected Cope rearrangement product ethyl alpha-cyano-2-allyl-3-benzo[b]thiopheneacetate (32) (6%) along with an unexpected diastereomeric mixture of 1-cyano-1-(ethoxycarbonyl)-2-methyl-2,3-dihydro-1H-benzo[b]cyclopenta[d]thiophenes(33)(18%). Speculative mechanistic considerations are offered regarding the mode of transformation of 12 to 16 and 32 to 33.

  DOI：

  10.1021/jo00068a034