JPS5922700B2 - Method for producing indole derivatives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing indole derivatives, and more specifically, indole is reacted in the presence of a cupric acetate-pyridine complex to produce 3,3'-diisodolyl and/or Alternatively, the present invention relates to a completely new method for producing 3,3'-diindolenylidene.

Conventionally, 3,3'-diisodryl has been produced by, for example, "Ga22etta chimica Italiana".
Italiana), 1939, Vol. 69, p. 562, and 3,3'-diindoleninylidene is, for example,
Journal of the Chemical Society (Jo
urnalofTheChemicalSociety
), 1957, p. 4141.

That is, indole is reacted with sulfur in a sealed tube, and 3
, 3'-diisodolyl was obtained, and 3,3'-diisodolyl and lead dioxide were further reacted in an ethyl acetate solvent to obtain 3,3'
- A method has been adopted to obtain diindolenylidene. These conventional methods are somewhat satisfactory when carried out on a laboratory scale, but when carried out on an industrial scale, there are various problems, such as the following.

(1) Since hydrogen sulfide gas is generated during the reaction, a pressure-resistant container must be used.

(2) The hydrogen sulfide generated is toxic and must be treated appropriately.

(3) The reaction is two-stage and the process is complicated.

As a result of intensive studies by the present inventors in an effort to resolve the above-mentioned drawbacks, we found that by using a cupric acetate-pyridine complex, 3,3'-diisodolyl and/or 3,3'-diindoleninyl can be converted from indole in one step. The present invention was achieved by discovering a completely new manufacturing method capable of obtaining reden. The present invention will be explained in detail below.

The reaction mode in the present invention does not require the use of a pressure vessel and can be carried out under normal pressure.

Although the reaction temperature cannot be determined uniquely in relation to the reaction time, a wide range from room temperature to 115°C, preferably from 60°C to 115°C can be adopted. Furthermore, where the reaction temperature is relatively low, 3,3'-diisodolyl is likely to be produced, and where the reaction temperature is relatively high, 3,3'-diisodolyl is likely to be produced.
- Diindolenylidene is more likely to be produced. Furthermore, as the reaction time increases, the amount of 3,3'-diindolenylidene produced increases. 5. As the solvent used in the present invention, various solvents such as pyridine, benzene, ethanol, methanol, etc. can be arbitrarily selected and used alone or in a mixture of two or more.

Although the solvent cannot be determined unambiguously, it is preferable to use pyridine in consideration of the solubility of indole and the cupric acetate-pyridine complex and the product, the boiling point of the solvent, etc.O Charge of cupric acetate to indole Although the weight ratio is arbitrary, for example, when pyridine is used as a solvent, a wide range of 1 to 150% by weight can be adopted.

Furthermore, when the weight ratio of cupric acetate to indole is relatively small, 3,3'-diindolyl is likely to be produced, and when it is relatively large, 3,3'-diindolenylidene is likely to be produced. Isolation and purification of 3,3 diindolyl and/or 3,3'-diindolenylidene from the reaction product is carried out as follows. That is, after concentrating the solvent used in the reaction under reduced pressure,
Furthermore, in order to remove the cupric acetate-pyridine complex in the reaction product, either washing with water or extraction using a suitable solvent is employed. Unreacted indole can also be removed, if desired, by steam distillation and/or recrystallization methods. Furthermore, if a highly pure target product is desired, it can be purified by column chromatography. During suspension polymerization or emulsion polymerization of a vinyl monomer mixture copolymerizable with this, it is highly effective as a coating agent for completely eliminating the adhesion of polymer scale on the walls of the polymerization machine.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Stirrer,
100 d of pyridine was placed in a four-bottle flask equipped with a thermometer, reflux condenser, and sample inlet, and 7.5 f of cupric acetate was placed in the flask. Gradually add while stirring.

The contents generate heat and turn dark blue, producing a cupric acetate-pyridine complex. Furthermore, indole 509 is pyridine 100
d and injected into the above-mentioned four-hole flask. After reacting at 80° C. for 8 hours, the reaction product was concentrated under reduced pressure.

The obtained product was extracted with 500 d of acetone to separate as much of the cupric acetate-pyridine complex as possible. The acetone extract was concentrated under reduced pressure to dryness. Furthermore, in order to remove a trace amount of cupric acetate in the product, the obtained product is repeatedly washed with an equal weight of water.b Unreacted indole is removed by steam distillation and product 239 is obtained. Obtained.

The obtained product was dissolved in ethanolivenzene = 1:9, separated and purified by column chromatography using silica gel, and 3,3'-diindolyl 59,3,
3'-Diindolenylidene 59 was obtained. The structure of the product can be confirmed by thin-layer chromatography and its melting point.
and Journal of the Chemical Society, 1957, p. 4141.
/--diindolenylidene.

Table 1 shows the Rf values and melting points of thin layer chromatography performed using silica gel (Wako Gel B-5F) as an adsorbent and ethanol livenzene = 1:9 as a developing solvent. , 3,3'-diindolyl and 3,3'-diindoleninylidene were confirmed to be produced.

The reaction was carried out in the same manner as in Example 1 except that the temperature was 60° C., and then the reaction product was concentrated under reduced pressure.

After washing was repeated five times with water of the same weight as the obtained product, unreacted indole was removed by steam distillation to obtain 16 g of a reaction product. Further, the reaction product was purified by the method shown in Example 1 to obtain 3,3'-diindolyl 59.
The results of thin layer chromatography and melting point measurements performed in the same manner as in Example 1 are shown in Table 2.

No formation of 3p3'-diindoleninylidene was observed. Example 3 The reaction and post-treatment were carried out in the same manner as in Example 1, except that cupric acetate was changed to 759, and product 259 was obtained. .

Purification was performed in the same manner as in Example 1 to obtain 3,37-diindoleninylidene 69.

The results of thin layer chromatography and melting point measurements performed in the same manner as in Example 1 are shown in Table 3. No formation of 3,3'-diindolyl was observed.

Claims (1)

[Claims] 1. In producing an indole derivative selected from the group consisting of 3,3'-diindolyl and 3,3'-diindolenylidene using indole as a starting material, it is recommended to use a cupric acetate-pyridine complex as a catalyst. Characteristic method for producing indole derivatives.