1990 Fiscal Year Final Research Report Summary
A Novel Synthesis of Indole and Quinoline Derivatives from Aniline and 1, 2- or 1, 3-Diols
| Project/Area Number |
01850192
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Synthetic chemistry
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
WATANABE Yoshihisa Kyoto University, Hydrocarbon Chemistry, Professor, 工学部, 教授 (70025956)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HONDA Tadatoshi Mitsui Toatsu Chemicals, Inc., Senior Research Scientist, 技術研究部, 主席研究員
KONDO Teruyuki Kyoto University, Hydrocarbon Chemistry, Instructor, 工学部, 助手 (20211914)
MITSUDO Takeaki Kyoto University, Hydrocarbon Chemistry, Associate Professor, 工学部, 助教授 (90026344)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Indole / Quinoline / Ruthenium catalyst / Homogeneous catalyst / Dehydrogenation / Heterocyclization |
|---|
| Research Abstract |
1. (1) Syntheses of Indole Derivatives from 2- (2-Aminophenyl) ethanol and 2- (2-Nitrophenyl) ethanol : When 2- (2-aminophenyl) ethanols (3), which were easily prepared by condensation between the corresponding 2-nitrotoluene (1) and aldehydes followed by reduction, were treated with a catalytic amount of RuCl_2(PPh_3)_3 (2 mol%) under reflux in toluene for 6 h, the corresponding indoles (4) were readily obtained in high to excellent yields (73-100 %).
1. (2) Plots of -ln vs time were linear over 70 % conversions of (3), where x is the amount of indoles (4) formed and a_0 is the amount of (3) charged. Furthermore, a straight line with a zero intercept was obtained on plotting the observed rate constants against the different initial catalyst concentrations ([RuCl6.10 x 10-2.44 x 10 mol dm^<-3>). Thus the rate law for the present indole synthesis is expressed by the following equation.
d[(4)]/dt=kappa_<obs>[RuCl_2(PPh_3)_3]_0[(3)]
1. (3) With a heterogeneous (Pd/C or Rh/C) and homogeneous (RuCl_2(PPh_3)_3 binary catalyst system, indoles were afforded in one pot from 2- (2-nitrophenyl) ethanols (2) under a hydrogen atmosphere.
2. (1) Synthesis of Indole from Aniline and Ethylene Glycol : When the reaction of aniline with ethylene glyol was performed (aniline/ethylene glycol=1.0/1.5) in the presence of a catalytic amount of RuCl, 1.4-diphenylpiperazine was mainly obtained. However, when the molar ration of aniline/ethylene glycol was increased from 1.0/1.5 to 10/1.0, indole was obtained in 8 % yield together with a considerable amount of N, N'-diphenylethylenediamine. At this stage, RuClO - dppe is the most suitable catalyst system for the synthesis of indole from aniline and ethylene glycol (18 % yield).
2. (2) N- (Trimethylsilyl) aniline and acetanilide, which were protected compounds of aniline, did not react with ethylene glycol and the corresponding indoles were not obtained at all.
|
