Enhanced regio-selectivity in glycol acylation

Patent metadata

Field	Value
Publication number	US-10023586-B2
Application number	US-201415102284-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 19, 2013
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A method for acid-catalyzed acylation of an isohexide is described. The method involves a reaction of an isohexide and an excess of carboxylic acid in the presence of a Lewis acid or a Brnsted acid catalyst. One or more Lewis acid or Brnsted acid can facilitate conversion of isohexides to their corresponding mono and diesters with a pronounced greater regio-selectivity of exo-OH over endo-OH of the isohexide in the product. Particular catalytic acid species include zirconium chloride (ZrCl4) and phosphonic acid (H3PO3), which manifest a ratio of exo:endo regioselectivity of about 5.0≠3:1 and about 4.00.3:1, respectively.

First claim

We claim:

1. A method for acid-catalyzed acylation of isosorbide, comprising contacting isosorbide with an excess of carboxylic acid in the presence of a Lewis acid catalyst at a reaction temperature and for a time sufficient to produce a corresponding monoester product with a ratio of exo/endo regioselectivity of at least 3.4:1, wherein said Lewis acid catalyst is selected from the group consisting of tin (II)-2-ethylhexanoate, dibutyl-tin (II) chloride, tin (II) chloride, hafnium chloride, dibutyl-tin maleate, titanium (IV) chloride, zirconium (IV) chloride, bismuth chloride, lanthanum (III) triflate, dibutyl-tin (IV) oxide, iron (III) triflate, aluminum chloride, bismuth triflate, gallium triflate, scandium triflate, and combinations of these.

2. The method according to claim 1 , wherein said reaction temperature is from 150° C. to 250° C.

3. The method according to claim 1 , wherein said reaction temperature is from 170° C. to 220° C.

4. The method according to claim 1 , wherein said reaction time is less than 24 hours.

5. The method according to claim 4 , wherein said reaction time is 5-12 hours.

6. The method according to claim 1 , wherein said carboxylic acid is selected from an alkanoic, alkenoic, alkyonoic, and aromatic acid, having a carbon chain length ranging from C 2 -C 26 .

7. The method according to claim 1 , wherein said carboxylic acid is present in 2-fold to 10-fold molar excess relative to the isosorbide.

8. The method according to claim 7 , wherein said carboxylic acid is present in 3-fold molar excess relative to the isosorbide.

9. The method according to claim 1 , wherein the ratio of said exo/endo regioselectivity ranges from about 3.5:1 to about 3.9:1.

10. The method according to claim 1 , wherein said Lewis acid is zirconium (IV) chloride.

11. The method according to claim 1 , wherein said Lewis acid is present in an amount of catalyst loading that ranges from 0.0001 wt. % to 10 wt. % relative to the isosorbide content.

Assignees

• Archer Daniels Midland Co

Inventors

• Stensrud Kenneth
• Hagberg Erik
• Rockafellow Erin

Classifications

• B01J27/10

  Chlorides · CPC title

• B01J31/0257

  Phosphorus acids or phosphorus acid esters · CPC title

• B01J31/0215

  Sulfur-containing compounds · CPC title

• C07D493/04 Primary

  Ortho-condensed systems · CPC title

• B01J31/0211

  with a metal-oxygen link · CPC title