A kind of regioselective synthesis method of 2,5-disubstituted pyrrole

A regioselective, disubstituted pyrrole technology, applied in organic chemistry and other directions, can solve the problems of limited substituents, complex product types, and high toxicity, and achieves the effect of good universality and simplified synthesis process.

Active Publication Date: 2019-05-10
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in these synthetic methods of pyrrole, the substituents at the 2,5-position on the pyrrole are all introduced before forming the pyrrole ring, which limits the introduction of substituents. At the same time, the cost of these synthetic routes is high and the raw materials are unstable. Or highly toxic, the types of products are more complicated, and the scope of application is limited

Method used

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  • A kind of regioselective synthesis method of 2,5-disubstituted pyrrole
  • A kind of regioselective synthesis method of 2,5-disubstituted pyrrole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] The first step, the synthesis of compound 2

[0036]Under nitrogen protection, add NaH (1.73g, 43.2mmol), DMF (50 mL) in 250mL two-necked flask; Add pyrrole (2.42g, 36mmol) and DMF (20mL) in 100mL two-necked flask, stir in ice bath Add it dropwise to the DMF solution of NaH washed with n-hexane, stir for 1h; add ClSO dropwise 2 NMe 2 (3.9mL, 36mmol), react at 0°C for 2h. Add an appropriate amount of ice water to the two-neck flask, extract with ether, collect the organic phase, wash with water and saturated brine, and anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure and then separated by column. The developer was n-hexane:ether (10:1) to obtain 4.39 g of white solid with a yield of 70.0%. mp:61-62℃; 1 H NMR (500MHz, CDCl 3 )δ2.79(s,6H),6.31(t,1H,J=2Hz),7.09(t,1H,J=2Hz); 13 C NMR (125MHz, CDCl 3 )δ38.3, 111.7, 120.9. HRMS (ESI-TOF) for C 6 h 10 N 2 o 2 S[M+H] + :calcd,175.0536.found 175.0536.

[0037] The second step, the...

Embodiment 2

[0078] The first step, the synthesis of compound 2

[0079] Under nitrogen protection, NaH (1.44g, 36mmol) and DMF (50 mL) were added to a 250mL two-necked flask; pyrrole (2.42g, 36mmol) and DMF (20mL) were added to a 100mL two-necked flask, and the Add dropwise to the DMF solution of NaH washed with n-hexane, stir for 1h; add ClSO dropwise 2 NMe 2 (3.9mL, 36mmol), react at 0°C for 2h. Add an appropriate amount of ice water to the two-neck flask, extract with ether, collect the organic phase, wash with water and saturated brine, and anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure and then separated by column. The developer was n-hexane:ether (10:1) to obtain 4.39 g of white solid with a yield of 80%.

[0080] The second step, the synthesis of compound 3

[0081] Under nitrogen protection, THF (60mL), TMP (2,2,6,6-tetramethylpiperidine) (8.05mL, 47.4mmol) were added to a 250mL two-necked flask, and n- BuLi (14.2mL / 2.5M, 36mmol), reacte...

Embodiment 3

[0110] The first step, the synthesis of compound 2

[0111] Under nitrogen protection, NaH (4.32g, 108mmol) and DMF (50 mL) were added to a 250mL two-necked flask; pyrrole (2.42g, 36mmol) and DMF (20mL) were added to a 100mL two-necked flask, and the Add dropwise to the DMF solution of NaH washed with n-hexane, stir for 3h; add ClSO dropwise 2 NMe 2 (7.8mL, 72mmol), react at room temperature for 5h. Add an appropriate amount of ice water to the two-neck flask, extract with ether, collect the organic phase, wash with water and saturated brine, and anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure and then separated by column. The developer was n-hexane:ether (10:1) to obtain 4.39 g of white solid with a yield of 70%.

[0112] The second step, the synthesis of compound 3

[0113] Under nitrogen protection, THF (60mL), TMP (2,2,6,6-tetramethylpiperidine) (8.05mL, 47.4mmol) were added to a 250mL two-necked flask, and n- BuLi (28.5mL / 2.5M, 7...

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Abstract

The invention discloses a region-selective synthesis method of 2,5-disubstituted pyrrole and belongs to the field of chemical synthesis. According to the method, simple pyrrole is used as a starting raw material, step-by-step iodination and coupling reaction are utilized, and six-step reaction is carried out, so that a series of 2,5-disubstituted pyrrole connected with different substituent groups, yields are more than or equal to 60% respectively, and structures are confirmed by virtue of 1H NMR, 13C NMR and HRMS. Compared with the traditional Paal-Knorr synthesis method, the region-selective synthesis method disclosed by the invention has the advantages that a building block molecule does not need to be constructed in advance, cheap and easy-to-get pyrrole is used as a raw material, a synthesis process is simplified, different substituent groups can be flexibly introduced to sites 2,5 of pyrrole, and a foundation is laid for synthesizing compounds such as drugs, molecular wires and macromolecular polymers.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a regioselective synthesis method of 2,5-disubstituted pyrrole. Background technique [0002] 2,5-disubstituted pyrrole is an important class of polysubstituted pyrrole compounds, which have good biological activity or photoelectric properties, and are commonly found in natural or non-natural products with biological activity. They are many drugs, porphyrin analogs, The main structural unit of polymers, alkaloids and amino acids. 2,5-disubstituted pyrrole has a good application prospect, and its synthesis research has attracted more and more attention. [0003] At present, the synthesis methods of 2,5-disubstituted pyrrole are mainly divided into two categories, namely the ring formation of chain compounds and the functionalization of pyrrole ring. At present, there are many applications of ring-forming chain compounds, such as the traditional Paal-Knorr synthesis ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D207/48
CPCC07D207/48
Inventor 刘建辉于启欣闵祥婷
Owner DALIAN UNIV OF TECH
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