RU2283837C1 - Method for production of quinoline alkyl-derivatives - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to method for production of derivatives of general formula

, wherein R is C₂H₅, C₃H₇, C₄H₉. Claimed method includes reaction of aniline with aliphatic aldehydes in presence of catalyst. Method is characterized in that as catalyst crystallohydrate of lanthanide trichloride (LnCl₃.6H₂O, Ln = Pr, Nd, Eu) and triisobutylaluminum (iso-Bu₃Al)in LnCl₃.6H₂O:(iso-Bu₃Al) molar ratio of 1:12 are used. Process is carried out in air, under atmospheric pressure and room temperature in toluene for 25 min. quinoline and derivatives thereof are useful in synthesis of cyan dyes, as extractants, sorbents and corrosion inhibitors.

EFFECT: simplified method with increased yield.

1 cl, 1 tbl, 7 ex

Description

The present invention relates to methods for producing heterocyclic compounds, specifically to a method for producing alkyl quinoline derivatives of the general formula

where R = C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ .

Quinoline and its derivatives are used in the synthesis of cyanine dyes, as extractants, sorbents, and corrosion inhibitors.

A known method (AS USSR No. 1416487, publ. 05.23.92. Bull. No. 19) for the preparation of alkyl quinoline derivatives in the reaction of condensation of aniline with aliphatic aldehydes in the presence of a catalyst consisting of FeCl ₃ : PPh ₃ : dimethyl sulfoxide (DMSO) in molar the ratio of FeCl ₃ : PPh ₃ : DMSO equal to 0.8-1.5: 2.0-4.0: 10-20, and the reaction temperature of 100-150 ° C, in an autoclave for 8 hours. The yield of the target products reaches 90-95%.

The disadvantages of this method include high energy consumption (high temperature, pressure and duration of the process), the need to use special equipment (autoclave) and the activator ligand PPh ₃ .

A known method (F.A. Selimov, U.M. Dzhemilev, O.A. Ptashko. Metal complex catalysis in the synthesis of pyridine bases. M: Chemistry, 2003, p.223-233) to obtain alkyl quinoline derivatives in the reaction of condensation of aniline with aliphatic aldehydes under the action of a catalyst based on LnCl ₃ : PPh ₃ : dimethylformamide (DMF) at a molar ratio of 0.4: 1.2: 13 and a reaction temperature of 100 ° C, in an autoclave for 6 hours in organic solvents. As lantands (Ln), Pr, Nd, Sm, Dy, Yb, Gd, Eu, Ho, La, Er, Lu, Tm were used. The maximum selectivity for 2,3-dialkylquinoline (91%) is achieved using PrCl ₃ and a solvent of ethanol. In toluene, selectivity is reduced to 67%.

The disadvantages of this method include high energy consumption (high temperature, pressure and duration of the process), the need to use special equipment (autoclave) and the activator ligand PPh ₃ , as well as the high cost of anhydrous LnCl ₃ produced only outside Russia, which necessitates their preliminary production (energy-intensive, labor-intensive synthesis, in an aggressive environment).

Thus, in the literature there is no information on the effective synthesis of quinoline alkyl derivatives at atmospheric pressure and room temperature using reagents based on crystalline hydrates of lanthanide trichlorides.

A new method is proposed for the preparation of quinoline alkyl derivatives.

The essence of the method consists in the interaction of aniline with aliphatic aldehydes in the presence of a catalyst LnCl ₃ · 6H ₂ O: triisobutylaluminum (iso-Bu ₃ Al) taken in a molar ratio of LnCl ₃ · 6H ₂ O: (iso-Bu ₃ Al) = 1: 12 . The reaction is carried out in an argon atmosphere at room temperature (20 ° C) and atmospheric pressure. The reaction time of 10-20 minutes, the yield of the target product 92-96%. Pr, Nd, Eu, Tb were used as Ln, and toluene was used as the solvent. The reaction proceeds according to the scheme.

The yield of the target product on crystalline hydrate PrCl ₃ · 6H ₂ About the maximum. With an increase in the temperature of the solution, the content of the resinous products increases.

Significant differences of the proposed method

1. The proposed method is based on the use of commercial crystalline hydrates of trichlorides of lanthanides and triisobutylaluminum as starting reagents without using the third component, the PPh ₃ activator ligand. The reaction proceeds at atmospheric pressure and room temperature in toluene with a higher yield of the target product. Known methods use anhydrous LnCl ₃ or FeCl ₃ , and the catalyst is a three-component system.

The proposed method has the following advantages:

1. The method allows to reduce the yield (92-96%) of the target product by reducing the interaction temperature.

2. The method allows to significantly reduce the temperature (from 100 ° C to 20 ° C), the synthesis time (from 6 hours to 20 minutes), does not require special equipment (autoclave) and thereby significantly simplify the synthesis and reduce the cost of the target product.

3. The method does not require the use of additional reagent ligand activator PPh ₃ , and the catalyst is a two-component system.

4. The method does not require the preliminary preparation of anhydrous salts of LnCl ₃ or FeCl ₃ (laborious, lengthy synthesis in a corrosive environment).

The method is illustrated by the following examples:

EXAMPLE 1. In a 50 ml glass reactor, previously purged with argon and mounted on a magnetic stirrer, 8 ml of toluene and 0.54 mmol of PrCl ₃ · 6H ₂ O crystalline hydrate are placed. With vigorous stirring, at room temperature, 6.48 mmol of iso-Bu is added under argon flow. ₃ Al. After gas evolution ceases (10-15 min), without turning off stirring, 20 mmol of aniline and 44 mmol of butyraldehyde are added to the solution. Stirring is continued for 20 minutes. Then the reaction mixture was extracted three times with ether (3 × 50 ml), the combined extracts were dried over anhydrous MgSO ₄ , the solvent was distilled off, and the remaining reaction mass was fractionated in vacuo. The yield of 2-propyl-3-ethyl quinoline is 96% (3.82 g).

Other examples confirming the method are shown in table 1.

Table 1. Example Aldehyde The composition of the catalyst at a molar ratio T, ° C Time min Exit, % Target product one Oil C ₄ H ₈ O TbCl ₃ · 6H2O: ISO-Bu ₃ Al
1:12 twenty twenty 92 2-Propyl-3-ethylquinoline 2 Also EuCl ₃ · 6H ₂ O: iso-Bu ₃ Al
1:12 twenty twenty 88 Also 3 - NdCl ₃ · 6H2O: ISO-Bu ₃ Al
1:12 twenty twenty 93 - four - PrCl ₃ · 6H ₂ O: ISO-Bu ₃ Al
1:12 twenty twenty 96 - 5 Valerian C ₅ H ₁₀ O PrCl ₃ · 6H ₂ O: ISO-Bu ₃ Al
1:12 twenty twenty 90 2-butyl-3-propylquinoline 6 Kapron C ₆ H ₁₂ O PrCl ₃ · 6H ₂ O: ISO-Bu ₃ Al
1:12 twenty twenty 89 2-amyl-3-butylquinoline

All experiments were carried out in toluene.

The resulting compounds have the following physicochemical characteristics:

2-Propyl-3-ethylquinoline. Oily liquid with a characteristic odor. T _bale = 118 ° C (1 mmHg). M ⁺ 199. Found,%: C 84.91; N, 7.01; H, 8.35. C ₁₄ H ₁₇ N. Calculated,%: C 84.42; N, 7.04; H, 8.54. IR spectrum, υ, cm ^-1 : 740, 780, 1000, 1510, 1620, 2930. ¹ H NMR spectrum (CDCl ₃ , δ, ppm): 1.08 t (3H, CH ₃ ); 1.23 t (3H, CH ₃ ); 1.71 m (2H, CH ₂ ); 2.68 K (2H, CH ₂ ); 2.85 t (2H, CH ₂ ); 7.3-8.1 m (5H, arom.).

2-butyl-3-propylquinoline. Oily liquid with a characteristic odor. T _bale = 143 ° C (1 mmHg). M ⁺ 227. Found,%: C 84.35; N, 6.02; H, 8.95. C ₁₆ H ₂₁ N. Calculated,%: C 84.58; N, 6.17; H, 9.25. IR spectrum, υ, cm ^-1 : 740, 780, 1000, 1510, 1620, 2930. ¹ H NMR spectrum (CDCl ₃ , δ, ppm): 1.1 t (3H, CH ₃ ); 1.25 t (3H, CH ₃ ); 1.68 m (2H, CH ₂ ); 1.73 m (2H, CH ₂ ); 1.82 t (2H, CH ₂ ); 2.71 q (2H, CH ₂ ); 7.28-8.07 m (5H, arom.)

2-amyl-3-butylquinoline. Oily liquid with a characteristic odor. T _bale = 156 ° C (1 mmHg). M ⁺ 255. Found,%: C 87.5; N, 5.2; H, 9.3. C ₁₈ H ₂₅ N. Calculated,%: C 87.71; N, 5.49; H, 9.8. IR spectrum, υ, cm ^-1 : 740, 780, 1000, 1510, 1620, 2930. ¹ H NMR spectrum (CDCl ₃ , δ, ppm): 1.12 t (3H, CH ₃ ); 1.27 t (3H, CH ₃ ); 1.78 m (2H, CH ₂ ); 1.86 m (2H, CH ₂ ); 1.86 m (2H, CH ₂ ); 1.97 m (2H, CH ₂ ); 2.13 m (2H, CH ₂ ); 2.38 m (2H, CH ₂ ); 2.83 k (2H, CH ₂ ); 2.97 t (2H, CH ₂ ); 7.3-8.12 m (5H, arom.)

Claims (1)

The method of obtaining alkyl quinoline derivatives of the General formula

where R = C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ , by reacting aniline (C ₆ H ₅ NH ₂ ) with aliphatic aldehydes of the general formula RCH ₂ CHO (where R is as defined above) in the presence of a catalyst, characterized in that crystalline lanthanide trichloride hydrate (LnCl ₃ · 6H ₂ O, Ln = Pr, Nd, Tb, Eu) and triisobutylaluminum (iso-Bu ₃ Al) taken in a molar ratio of LnCl ₃ · 6Н ₂ O: (iso-Bu ₃ Al) = 1: 12, and the process is carried out at atmospheric pressure and room temperature temperature in toluene for 20 min in an argon atmosphere.