CN109503604A - Benzimidazole benzimidazole derivative and its synthetic method - Google Patents

Abstract

The invention discloses general structure L2 compound represented, wherein R₁Selected from hydrogen atom, the alkyl of C1~C6, the alkoxy of C1~C6, phenyl, cyano, trifluoromethyl, halogen radical, R2 is selected from the alkyl of phenyl, cyclohexyl, C1~C6.The present invention is raw material using benzimidazole methylamine derivative, in FeCl₃∙6H₂Under O catalysis, using isopropanol as solvent, target compound is obtained by solvent thermal reaction one kettle way, provides easy and environmental-friendly synthetic method to synthesize the nitrogen-containing heterocycle compound of this type.

Description

Benzimidazole benzimidazole derivative and its synthetic method

Technical field

The present invention relates to benzimidazole benzimidazole derivative and its synthetic methods, in particular to a kind of to pass through one pot of solvent heat The method of method synthesizing benzimidazole benzimidazole derivative.

Background technique

Benzimidazole and imidazole and its derivants have potential in terms of rice blast prevention and treatment, biological medicine and complex shine Using, therefore have received widespread attention.Prior synthesizing method elder generation synthesizing amide intermediate, then intramolecular cyclization, and need Using to the disagreeableness POCl of environment₃Equal reagents, to limit the synthesis of this kind of compound.

Solvent thermal reaction will simple raw material and solvent it is closed in a kettle, be placed in it is suitable at a temperature of reacted. The reaction in recent years is widely used in synthesizing the compound for the structure novel that conventional method is difficult to, these compounds usually exist There is potential application on light, electricity, magnetic, catalysis and biology.It is worth noting that, ligand is it some times happens that original under the conditions of solvent heat Position reaction, forms new organic matter, and therefore, solvent thermal reaction to synthesize there is the complicated molecule of specific function to provide new side Method.

Summary of the invention

The object of the present invention is to provide the benzimidazole benzimidazole derivatives of a kind of structure novel；

It is a further object to provide the preparation methods of above-mentioned benzimidazole benzimidazole derivative；

The present invention realizes that process is as follows:

Compound shown in general structure L2,

R₁Selected from hydrogen atom, the alkyl of C1~C6, the alkoxy of C1~C6, phenyl, cyano, trifluoromethyl, halogen radical；

R2 is selected from the alkyl of phenyl, cyclohexyl, C1~C6.

The preparation method of above compound:

Compound L 1 is dissolved in isopropanol, the Iron(III) chloride hexahydrate of catalytic amount is added, it is closed anti-under the conditions of 80 ~ 140 DEG C It should obtain compound L 2.

The present invention utilizes L1(such as benzimidazole methylamine) it is raw material, in FeCl₃∙6H₂Under O catalysis, using isopropanol as solvent, Target compound benzimidazole benzimidazole derivative L2 is obtained by solvent thermal reaction one kettle way, in addition, utilizing electrospray ionization mass spectrum The solvent and reaction time of reaction are screened, it is determined that FeCl₃·6H₂The important function of O catalyst.On this basis, Possible reaction mechanism is proposed, provides easy and environmental-friendly synthesis side to synthesize the nitrogen-containing heterocycle compound of this type Method.

Detailed description of the invention

Fig. 1 is the mono-crystalline structures figure of compound L 2；

Fig. 2 is the nucleus magnetic hydrogen spectrum of compound L 2, carbon spectrum and DEPT-135 spectrum；

Fig. 3 is electro-spray ionization high resolution mass spectrum figure and the mass-fragments fitting of compound L 2；

Fig. 4 is the thermogravimetric analysis figure of compound L 2；

Fig. 5 is the infrared figure of compound L 2；

Fig. 6 is that the ultraviolet spectra of compound L 2 absorbs figure；

Fig. 7 is the fluorescent emission spectrogram of compound L 2；

Fig. 8 is the mass spectrogram that L1 and FeCl3 6H2O reacts in different alcoholic solvents；

Fig. 9 is the mass spectrogram that L1 and FeCl3 6H2O reacts different time in isopropanol；

Figure 10 is the mass spectrogram that FeCl3 6H2O influences reaction；

Figure 11 is the possible formation mechenism of compound L 2.

Specific embodiment

It is specific below by way of being completed according to technical solution of the present invention of providing of inventor for clearer understanding invention Embodiment is described in further detail to the present invention.

Embodiment 1:L2(R₁ = H, R₂ = CH₃) synthesis and structural analysis

The N- tolimidazole methylamine (161.0 mg) of 1.0 mmol is added to the polytetrafluoroethylene (PTFE) that volume is 100.0 mL Reaction kettle in, be added 40.0 mL isopropanol dissolution after, add the Iron(III) chloride hexahydrate (54.0 mg) of 0.2 mmol, Stirring 5 minutes, sealing, is put into 140 DEG C of microwave dissolver and reacts 10 min, is then spin-dried for mother liquor, sample preparation and carries out column Chromatography, product spread to obtain light yellow monocrystalline by interface, belong to monoclinic system,P21 space groups, cell parameter area =5.4720 (1),b=8.9105 (2),c=15.3895 (4),α = 90 ^o,β = 99.801(2) ^o,γ = 90 ^o.Nuclear magnetic data also demonstrates the mono-crystalline structures:¹H NMR (CD₂Cl₂, 500 MHz) 9.45 (d, J = 10.0 Hz, 1H ArH), 7.94-7.91 (m, 1H, ArH), 7.44-7.42 (m, 2H, ArH), 7.37-7.55 (m, 2H, ArH), 7.30-7.27 (m, 1H, ArH), 7.23 (d, J = 10.0 Hz, 1H, ArH), 6.84 (s, 1H), 4.37 (s, 3H, CH₃), 3.75 (s, 3H, CH₃). ¹³C{¹H} NMR (CD₂Cl₂, 125 MHz): 144.2, 142.9, 142.7, 139.2, 136.6, 125.9, 125.2, 122.6, 122.2, 119.7, 119.4, 117.5, 109.3, 108.2, 98.9, 77.2, 32.1, 30.5。

Characterization of The Products test:

Fig. 1 is the mono-crystalline structures figure of L2, the results showed that L2 is by benzimidazole and benzimidazole and two nitrogen-containing heterocycle structures of imidazoles At dihedral angle 13.3o shows the structure of L2 without completely coplanar；

The nucleus magnetic hydrogen spectrum and carbon spectrum and DEPT-135 spectrum that Fig. 2 is L2.At room temperature, the core of L2 is carried out on 500 MHz of Bruker The test of magnetic resonance spectrogram, takes the L2 of 15.0 mg to be dissolved in the CD2Cl2 of 0.5 mL and is tested, obtained spectrogram result and monocrystalline Structure matches；

Fig. 3 is that the electro-spray ionization high resolution mass spectrum figure of L2 takes 1 monocrystalline to be dissolved in chromatographic grade acetonitrile at room temperature, The data acquisition under cation mode, peak of the m/z at 302.1406 are carried out on Thermo Exactive Plus ESI-MS For molecular ion peak [L2+H]+；

Fig. 4 is the thermogravimetric analysis figure of compound L 2, weighs the L2 of 6 mg at room temperature, and L2 heat is carried out on Netzsch TG209F3 Steady testing, wherein heating interval is 25-800 oC, and heating rate is 5 oC/min, and nitrogen flow rate is 15 mL/min, as a result Show that L2 starts to decompose at 220 DEG C under nitrogen atmosphere；

Fig. 5 is the infrared figure of compound L 2.At room temperature, the red of L2 is carried out on Bruker FTIR spectrophotometer Outer test, takes the L2 of 0.1 mg that KBr tabletting is made, and test scope is 4000-400 cm-1；

Fig. 6 is that the ultraviolet spectra of compound L 2 absorbs figure.At room temperature, in Agilent Cary 6000UV-Vis-NIR The upper acetonitrile solution (10-5 mol L-1) to L2 of spectrophotometer is tested.As shown in fig. 6, the acetonitrile of L2 is molten Liquid has maximum absorption band in 296 nm and 380 nm, can be attributed to π-π * transition；

Fig. 7 is the fluorescent emission spectrogram of compound L 2.At room temperature to the acetonitrile solution of L2 on the FLS-980 luminoscope of Edinburg (10-5 mol L-1) is tested.As shown in fig. 7, in the case where wavelength is the excitation of 249 nm light, in Visible-to-Near InfaRed (370-480 Nm) there is fluorescent emission, wherein 434 nm are the transition of intramolecular, 510 nm are intermolecular pi-pi accumulation；

Fig. 8 is the mass spectrogram that L2 and FeCl3 6H2O reacts in different alcoholic solvents, illustrates the use of isopropanol solvent to final The synthesis of product plays very special effect；

Fig. 9 is the mass spectrogram that L2 and FeCl3 6H2O reacts different time in isopropanol；

Figure 10 is the mass spectrogram that FeCl3 6H2O influences reaction；Illustrate that catalyst Fe Cl3 6H2O is essential；

Figure 11 is the possible formation mechenism of compound L 2.According to document, the possible reaction mechanism of initial guess: ligand L 1 first It is coordinated with FeCl3, then ligand occurs to aoxidize and self condenses to obtain imine intermediate, intramolecular nucleophilic addition/cyclization then occurs, Dehydrogenation obtains the Fe complex of L2 again, and dissociation finally occurs and obtains L2.

Embodiment 2: the similar compound of structure of the present invention

Benzimidizole derivatives are prepared using different raw materials referring to embodiment 1, result is as shown in the table.

Claims (4)

1. general structure L2 compound represented,

In above formula, R₁Selected from hydrogen atom, the alkyl of C1~C6, the alkoxy of C1~C6, phenyl, cyano, trifluoromethyl, halogen radical；

R2 is selected from the alkyl of phenyl, cyclohexyl, C1~C6.

2. compound according to claim 1, it is characterised in that: R₁ = H, R₂ = CH₃。

3. the preparation method of compound described in claim 1, it is characterised in that:

Compound L 1 is dissolved in isopropanol, the Iron(III) chloride hexahydrate of catalytic amount is added, it is closed anti-under the conditions of 80 ~ 140 DEG C It should obtain compound L 2.

4. compound described in claim 1 is preparing the application in fluorescent material.