Method for preparing cyclopenta[c]chromium compound

Patent metadata

Field	Value
Publication number	US-11358945-B2
Application number	US-202117163480-A
Country	US
Kind code	B2
Filing date	Jan 31, 2021
Priority date	Jul 30, 2018
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

The present invention discloses a method for preparing a cyclopenta[c]chromene compound. A cationic rare earth compound [Ln(CH)3CN)9]3+[(AlCl4)3]3−.CH3CN is used as a catalyst, and p-methyl thiophenol is used as an accelerator for a catalytic reaction of a chalcone compound so as to prepare a product; and Ln, contained in the catalyst, represents a positive trivalent rare earth metal ion and is selected from one of La, Nd, Sm, Gd and Yb. According to the method, the starting materials are easy to obtain, the reaction process is simple, the catalyst usage is low, the catalyst is universally applicable to various substituted 2-hydroxy chalcones, and the obtained cyclopenta[c]chromene compound has not been reported. The catalyst synthesis method is simple and easy to obtain, and the yield of the target product is high.

First claim

The invention claimed is:

1. A method for preparing a cyclopenta[c]chromene compound, comprising the following steps: under anhydrous and anaerobic conditions, using a chalcone compound as a reactant, using a cationic rare earth compound as a catalyst, using p-methyl thiophenol as an accelerator, and reacting in an organic solvent to prepare the cyclopenta[c]chromene compound, wherein
the cationic rare earth compound has the following chemical structure:

wherein, Ln represents a positive trivalent rare earth metal ion;
the chalcone compound has the following chemical structure:

wherein, R 1 is selected from the group consisting of hydrogen, 3-chloro, 4-chloro, 4-methoxy, 5-chloro, 5-bromo, 5-methyl, 5-methoxy, and 6-chloro; R 2 is selected from the group consisting of hydrogen, 3′-chloro, 3′-bromo, 3′-methoxy, 4′-chloro, 4′-bromo, 4′-phenyl, and 4′-methoxy.

2. The method for preparing the cyclopenta[c]chromene compound according to claim 1 , wherein the organic solvent is selected from the group consisting of chlorobenzene, acetonitrile, dichloroethane, and toluene; Ln is selected from the group consisting of La, Nd, Sm, Gd, and Yb; the anhydrous and oxygen-free conditions are inert atmosphere conditions.

3. The method for preparing the cyclopenta[c]chromene compound according to claim 2 , wherein the organic solvent is chlorobenzene and the Ln is Ytterbium.

4. The method for preparing the cyclopenta[c]chromene compound according to claim 1 , wherein a molar ratio of the catalyst:the chalcone compound:the accelerator is (0.01 to 0.08):1:(0.6 to 1.3).

5. The method for preparing the cyclopenta[c]chromene compound according to claim 4 , wherein the molar ratio of the catalyst:the chalcone compound:the accelerator is (0.02 to 0.05):1:(1.1 to 1.2).

6. The method for preparing a cyclopenta[c]chromene compound according to claim 1 , wherein a reaction temperature is 80 to 140 ° C.; and a reaction time is 24 to 72 hours.

7. The method for preparing the cyclopenta[c]chromene compound according to claim 6 , wherein the reaction temperature is a reflux temperature of the organic solvent, and the reaction time is 36 hours.

Assignees

• Univ Soochow

Inventors

• Xu Fan
• Li Dandan
• Ding Xiaoyou
• Zhu Yanan
• Yao Zhigang

Classifications

• C07D311/94 Primary

  condensed with rings other than six-membered or with ring systems containing such rings · CPC title

• B01J31/0252 Primary

  with a metal-nitrogen link, e.g. metal amides, metal guanidides · CPC title

• B01J2531/37

  Lanthanum · CPC title

• B01J31/0231

  Halogen-containing compounds · CPC title

• B01J2531/38

  Lanthanides other than lanthanum · CPC title