A Novel Synthesis of Indole and Quinoline Derivatives from Aniline and 1, 2- or 1, 3-Diols

1. (1)以2-（2-氨基苯基）乙醇和2-（2-硝基）乙醇为原料合成吲哚衍生物：2-（2-氨基苯基）乙醇是由相应的2-硝基甲苯(1)与醛缩合后还原制备的2-（2-氨基苯基）乙醇(3)，用催化量为2 mol%的RuCl_2(PPh_3)_3在甲苯中回流6 h，可得到相应的吲哚(4)，收率可达73 ~ 100% .1。(2) -ln与时间的曲线在(3)的70%转换后呈线性关系，其中x是形成的吲哚(4)的量，a_0是带电的(3)的量。此外，在不同初始催化剂浓度（[RuCl6.10 × 10-2.44 × 10 mol dm^<-3>）下绘制了观察到的速率常数，得到了一条截距为零的直线。因此，本文所述吲哚合成的速率规律表示为：d[(4)]/dt=kappa_<obs>[RuCl_2(PPh_3)_3]_0[(3)]1。(3)采用非均相（Pd/C或Rh/C）和均相（RuCl_2(PPh_3)_3）二元催化剂体系，在氢气气氛下，由2-（2-硝基苯）乙醇(2)在一锅中生成吲哚。(1)苯胺与乙二醇合成吲哚：当苯胺与乙二醇反应时（苯胺/乙二醇=1.0/1.5），在催化量的RuCl存在下，主要得到1.4-二苯哌嗪。当苯胺/乙二醇的摩尔比由1.0/1.5增加到10/1.0时，吲哚和N， N'-二苯乙二胺的收率为8%。在此阶段，RuClO - dppe是苯胺和乙二醇合成吲哚最合适的催化剂体系（产率为18%）。(2)苯胺的保护化合物N-（三甲基硅基）苯胺和乙酰苯胺不与乙二醇反应，也没有得到相应的吲哚。

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.