Preparation method of selenium-containing heterocyclic compounds

Patent metadata

Field	Value
Publication number	US-11548862-B2
Application number	US-202117527544-A
Country	US
Kind code	B2
Filing date	Nov 16, 2021
Priority date	Nov 27, 2020
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

A reaction of azacyclopropane derivative with elemental selenium and TMSCN to construct a selenium-containing heterocycle under metal-free and additive-free conditions is provided. The new strategy features no metal participation, no additive promotion, a wide substrate selection range and a good functional group compatibility, and provides an efficient and green approach to constructing a variety of selenium-containing heterocyclic compounds in a highly concise way.

First claim

What is claimed is:

1. A preparation method of a selenium-containing heterocyclic compound, comprising the following steps:
sequentially adding azacyclopropane derivative of formula I, selenium powder, trimethylsilyl cyanide (TMSCN) and an organic solvent to a reactor equipped with a magnetic stirrer,
subsequently replacing atmosphere in the reactor with an inert atmosphere, heating and stirring for reaction to obtain a reaction mixture,
diluting the reaction mixture with ethyl acetate after the reaction, and then filtering through a silica gel pad to obtain a filtrate,
concentrating the filtrate under a reduced pressure to obtain a residue, and then purifying the residue by silica flash chromatography, thereby obtaining a selenium-containing heterocyclic compound of formula II;
wherein a formula for the reaction is as follows:

where n=2;
where adjacent two R 1 /R 2 substituent groups are connected to each other and form a benzene ring structure together with carbon atoms connecting the adjacent two R 1 /R 2 substituent groups, and adjacent two R 2 /R 3 substituent groups each are hydrogen group;
wherein the organic solvent is one selected from alcoholic solvents.

2. The preparation method according to claim 1 , wherein the organic solvent is one selected from the group consisting of methanol, ethanol and isopropanol.

3. The preparation method according to claim 1 , wherein the organic solvent is isopropanol.

4. The preparation method according to claim 1 , wherein reaction temperature of the heating and stirring for reaction is 80˜120° C., reaction time of the heating and stirring for reaction is 4˜48 hours (h).

5. The preparation method according to claim 4 , wherein the reaction temperature is 100° C., and the reaction time is 12˜24 h.

6. The preparation method according to claim 5 , wherein the reaction time is 24 h.

7. The preparation method according to claim 1 , wherein a molar ratio of the azacyclopropane derivative of the formula I, the selenium powder and the TMSCN is 1:(2˜5):(1˜3).

8. The preparation method according to claim 7 , wherein the molar ratio of the azacyclopropane derivative of the formula I, the selenium powder and the TMSCN is 1:3:2.

9. The preparation method according to claim 1 , wherein the inert atmosphere is one of nitrogen atmosphere and argon atmosphere.

10. The preparation method according to claim 1 , wherein the inert atmosphere is argon atmosphere.

Assignees

• Univ Wenzhou

Inventors

• Liu Miaochang
• Lu Liguo
• Chen Chuanli
• Zhou Yunbing
• Wu Huayue

Classifications

• C07D293/08

  Six-membered rings · CPC title

• C07D293/02 Primary

  not condensed with other rings · CPC title

• C07D293/10

  condensed with carbocyclic rings or ring systems · CPC title

• C07D293/06 Primary

  Selenazoles; Hydrogenated selenazoles · CPC title