Process for the synthesis of aryl sulfones

Patent metadata

Field	Value
Publication number	US-9650330-B2
Application number	US-201415103567-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Dec 12, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

The present patent discloses a novel, efficient and transition-metal-free room temperature single step process for synthesis of aryl sulfones and substituted aryl sulfones starting from aryl substrates.

First claim

The invention claimed is:

1. A room temperature single step process for synthesis of compound of Formula I

wherein, R is selected from H, alkyl (C 1 -C 6 ), aryl, heteroaryl, O-, S-, N-, P-alkyl/unsubstituted and substituted aryl;
R′ is selected from alkyl (C 1 -C 6 ), aryl, heteroaryl, O-, S-, N-, P-alkyl/unsubstituted and substituted aryl;
comprising the steps of:
a. adding benzyne precursor of Formula II to a stirred solution of fluoride ion source and compound of Formula III in the ratio ranging between 1:1 to 1:1.1 in anhydrous acetonitrile to obtain a reaction mixture;

wherein, R is selected from H, alkyl, aryl, heteroaryl, O-, S-, N-, P-alkyl/unsubstituted and substituted aryl;
R′ is selected from, alkyl, aryl, heteroaryl, O-, S-, N-, P-alkyl/unsubstituted and substituted aryl;
X is selected from H, Li, Na, K, Cs;

b. stirring the reaction mixture of step (a) for the period in the range of 1 to 8 hours followed by purification to obtain the desired product I.

2. The process according to claim 1 , wherein the fluoride ion source is selected from the group consisting of TBAF (Tetra-n-butylammonium fluoride), CsF (Cesium fluoride), NaF (Sodium Fluoride), RbF (Rubidium fluoride) or KF (Potassium fluoride).

3. The process according to claim 1 , wherein the fluoride ion source is selected from TBAF or CsF.

4. The process according to claim 1 , wherein the compound of formula I is selected from the group consisting of:
1-Phenyl (sulfonyl)benzene (3);
1,2-Difluoro-4-(phenylsulfonyl)benzene (5);
1,2-Dimethyl-4-(phenylsulfonyl)benzene (7);
1,4-Dimethyl-2-(phenylsulfonyl)benzene (9);
1-Methoxy-3-(phenylsulfonyl)benzene (11);
1,3-Dimethoxy-5-(phenylsulfonyl)benzene (13);
1,2-Dimethoxy-4-(phenylsulfonyl)benzene (15);
5-(Phenylsulfonyl)benzo[d][1,3]dioxole (17);
(Methylsulfonyl)benzene (19);
(Butylsulfonyl)benzene (21);
1-Methyl-4-(phenylsulfonyl)benzene (23);
1-(Tert-butyl)-4-(phenylsulfonyl)benzene (25);
1-Methoxy-4-(phenylsulfonyl)benzene (27);
1-(4-(phenylsulfonyl)phenyl)ethan-1-one (29);
1-Nitro-4-(phenylsulfonyl)benzene (31);
1-Fluoro-4-(phenylsulfonyl)benzene (33) and;
2-bromo-5-(phenylsulfonyl)thiophene (35).

5. The process according to claim 1 , wherein the compound of formula II is selected from the group consisting of:
2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (1)
4,5-difluoro-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (4)
4,5-dimethyl-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (6)
3,6-dimethyl-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (8)
3-methoxy-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (10)
3,5-dimethoxy-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (12)
4,5-dimethoxy-2-(trimethylsilyl)phenyl trifluoromethane-sulfonate (14) and
6-(trimethylsilyl)benzo[d][1,3]dioxol-5-yl trifluoromethane-sulfonate (16).

6. The process according to claim 1 , wherein the compound of formula III is selected from the group consisting of:
sodium benzenesulfinate (2)
sodium methanesulfinate (18)
sodium butane-1-sulfinate (20)
sodium 4-methylbenzenesulfinate (22)
sodium 4-(tert-butyl)benzenesulfinate (24)
sodium 4-methoxybenzenesulfinate (26)
sodium 4-acetylbenzenesulfinate (28)
sodium 4-nitrobenzenesulfinate (30)
sodium 4-fluorobenzenesulfinate (32) and
Sodium 5-bromothiophene-2-sulfinate (34).

7. The process according to claim 1 , wherein the yield of the compound of formula I is in the range of 45-96%.

Assignees

• Council Scient Ind Res

Inventors

• Mhaske Santosh Baburao
• Pandya Virat

Classifications

• C07C317/14

  having sulfone or sulfoxide groups bound to carbon atoms of six-membered aromatic rings · CPC title

• C07D333/34

  Sulfur atoms · CPC title

• C07C315/04 Primary

  by reactions not involving the formation of sulfone or sulfoxide groups · CPC title

• C07C317/22

  with sulfone or sulfoxide groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton · CPC title

• C07D317/46

  condensed with one six-membered ring · CPC title