1-(3,4-Dihydro-benzo[c][1,2]oxazin-1-yl)-2-ethyl-butan-1-one | 180985-71-1

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 苯并恶嗪类
• 英文名称: 1-(3,4-Dihydro-benzo[c][1,2]oxazin-1-yl)-2-ethyl-butan-1-one
• 英文别名: 1-(3,4-Dihydro-2,1-benzoxazin-1-yl)-2-ethylbutan-1-one
• CAS: 180985-71-1
• 化学式: C₁₄H₁₉NO₂
• 分子量: 233.31
• InChiKey: JVOAKIQSDJTQMM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.1
• 重原子数：
  17
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  29.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  1-(3,4-Dihydro-benzo[c][1,2]oxazin-1-yl)-2-ethyl-butan-1-one 生成 聚合甲醛 、 2-(1-ethylpropyl)-4H-3,1-benzoxazine
  参考文献：
  名称：

  Rearrangement of N-acyl-3,4-dihydro-1H-2,1-benzoxazines to 2-substituted-4H-3,1-benzoxazines through a retro-Diels–Alder extrusion of formaldehyde

  摘要：

  N-Acyl-3,4-dihydro-1H-2,1-benzoxazines (3) undergo a thermal decomposition involving loss of formaldehyde in a retro-Diels-Alder reaction. The resultant N-acylazaxylylenes dagger (4) undergo a 6 pi electrocyclisation to give 2-substituted-4H-3, 1-benzoxazines (5) rather than a 4 pi electrocyclisation to give the N-acyl-1,2-dihydrobenzazetes (6). Compounds 5 have been fully characterised spectroscopically and their data is inconsistent with that reported previously by other workers for what are purported to be the same compounds. 2-Methyl-4H-3,1-benzoxazine (5b) and other 2-alkyl-substituted compounds undergo facile hydrolysis to o-aminobenzyl esters (9) which rearrange to the thermodynamically more stable o-hydroxymethylanilides (10). 2-Phenyl-4H-3,1-benzoxazine (5a) is relatively stable to hydrolysis but undergoes a novel photochemical ring opening (> 254 nm) to give the N-benzoylazaxylylene (12) which can be trapped with alcohols giving o'-alkoxymethylbenzanilides (11). In cyclohexanol at 160 degrees C, the intermediate in the thermal rearrangement of 3a to 5a, N-benzoylazaxylylene (12), was trapped as o'-cyclohexyloxymethylbenzanilide (11b). The rearrangements in mesitylene are unimolecular with activation energies of 35, 37 and 42 kcal mol(-1)double dagger for 3a; 3c and 3d,.respectively. The extrusion and electrocyclisation reaction pathways for N-acetyl-3,4-dihydro-2, 1-benzoxazine (3b) have been modelled using AM1 molecular orbital theory which predicts both a non-synchronous transition state for the retro-Diels-Alder reaction and the preferred mode of ring closure to be the 6 pi rather than the 4 pi electrocyclisation.

  DOI：

  10.1039/p29960001367
• 作为产物：
  描述：

  O-(2-phenylethyl) N-chloro-2-ethylbutyrohydroxamate 在 silver tetrafluoroborate 作用下， 以 乙醚 为溶剂， 以17%的产率得到1-(3,4-Dihydro-benzo[c][1,2]oxazin-1-yl)-2-ethyl-butan-1-one
  参考文献：
  名称：

  Rearrangement of N-acyl-3,4-dihydro-1H-2,1-benzoxazines to 2-substituted-4H-3,1-benzoxazines through a retro-Diels–Alder extrusion of formaldehyde

  摘要：

  N-Acyl-3,4-dihydro-1H-2,1-benzoxazines (3) undergo a thermal decomposition involving loss of formaldehyde in a retro-Diels-Alder reaction. The resultant N-acylazaxylylenes dagger (4) undergo a 6 pi electrocyclisation to give 2-substituted-4H-3, 1-benzoxazines (5) rather than a 4 pi electrocyclisation to give the N-acyl-1,2-dihydrobenzazetes (6). Compounds 5 have been fully characterised spectroscopically and their data is inconsistent with that reported previously by other workers for what are purported to be the same compounds. 2-Methyl-4H-3,1-benzoxazine (5b) and other 2-alkyl-substituted compounds undergo facile hydrolysis to o-aminobenzyl esters (9) which rearrange to the thermodynamically more stable o-hydroxymethylanilides (10). 2-Phenyl-4H-3,1-benzoxazine (5a) is relatively stable to hydrolysis but undergoes a novel photochemical ring opening (> 254 nm) to give the N-benzoylazaxylylene (12) which can be trapped with alcohols giving o'-alkoxymethylbenzanilides (11). In cyclohexanol at 160 degrees C, the intermediate in the thermal rearrangement of 3a to 5a, N-benzoylazaxylylene (12), was trapped as o'-cyclohexyloxymethylbenzanilide (11b). The rearrangements in mesitylene are unimolecular with activation energies of 35, 37 and 42 kcal mol(-1)double dagger for 3a; 3c and 3d,.respectively. The extrusion and electrocyclisation reaction pathways for N-acetyl-3,4-dihydro-2, 1-benzoxazine (3b) have been modelled using AM1 molecular orbital theory which predicts both a non-synchronous transition state for the retro-Diels-Alder reaction and the preferred mode of ring closure to be the 6 pi rather than the 4 pi electrocyclisation.

  DOI：

  10.1039/p29960001367

文献信息

• Rearrangement of N-acyl-3,4-dihydro-1H-2,1-benzoxazines to 2-substituted-4H-3,1-benzoxazines through a retro-Diels–Alder extrusion of formaldehyde
  作者：Stephen A. Glover、Katherine M. Jones、Ian R. McNee、Colleen A. Rowbottom

  DOI：10.1039/p29960001367

  日期：——

  N-Acyl-3,4-dihydro-1H-2,1-benzoxazines (3) undergo a thermal decomposition involving loss of formaldehyde in a retro-Diels-Alder reaction. The resultant N-acylazaxylylenes dagger (4) undergo a 6 pi electrocyclisation to give 2-substituted-4H-3, 1-benzoxazines (5) rather than a 4 pi electrocyclisation to give the N-acyl-1,2-dihydrobenzazetes (6). Compounds 5 have been fully characterised spectroscopically and their data is inconsistent with that reported previously by other workers for what are purported to be the same compounds. 2-Methyl-4H-3,1-benzoxazine (5b) and other 2-alkyl-substituted compounds undergo facile hydrolysis to o-aminobenzyl esters (9) which rearrange to the thermodynamically more stable o-hydroxymethylanilides (10). 2-Phenyl-4H-3,1-benzoxazine (5a) is relatively stable to hydrolysis but undergoes a novel photochemical ring opening (> 254 nm) to give the N-benzoylazaxylylene (12) which can be trapped with alcohols giving o'-alkoxymethylbenzanilides (11). In cyclohexanol at 160 degrees C, the intermediate in the thermal rearrangement of 3a to 5a, N-benzoylazaxylylene (12), was trapped as o'-cyclohexyloxymethylbenzanilide (11b). The rearrangements in mesitylene are unimolecular with activation energies of 35, 37 and 42 kcal mol(-1)double dagger for 3a; 3c and 3d,.respectively. The extrusion and electrocyclisation reaction pathways for N-acetyl-3,4-dihydro-2, 1-benzoxazine (3b) have been modelled using AM1 molecular orbital theory which predicts both a non-synchronous transition state for the retro-Diels-Alder reaction and the preferred mode of ring closure to be the 6 pi rather than the 4 pi electrocyclisation.