Synthesis of alkylfurans

Patent metadata

Field	Value
Publication number	US-9868712-B2
Application number	US-201414915186-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 30, 2013
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

The invention provides a method for preparing a 2,5-dialkyl furan. The method includes forming a reaction mixture containing a catalyst, a hydrogen source, and 2-haloalkylfuran starting material under conditions sufficient to form the 2,5-dialkyl furan. The 2-haloalkylfuran starting material can be derived from biomass, and the 2,5-dialkyl furan product can be used as a biofuel or as a chemical feedstock.

First claim

What is claimed is:

1. A method for preparing a compound of formula I:

the method comprising
forming a first reaction mixture comprising a carbonyl derivatizing agent, an acid, and a compound of formula IIa

under conditions sufficient to form a compound of formula IIb:

forming a reaction mixture comprising a catalyst, a hydrogen source, and the compound of formula IIb,
under conditions sufficient to form the compound of formula I;

wherein
R 1 and R 2 are independently C 1-18 alkyl;
R 1a is selected from the group consisting of H and C 1-17 alkyl;
R 2a is C 1-18 haloalkyl;
R 3a is selected from the group consisting of H, C 1-6 alkyl, and C 1-6 acyl; and
R 4a is selected from the group consisting of C 1-6 alkyl and C 1-6 acyl, or
R 3a and R 4a are taken together to form C 2-4 alkylene.

2. The method of claim 1 , wherein the carbonyl derivatizing agent is selected from the group consisting of an orthoester, a C 1-6 alkanol, a C 2-4 alkane-diol, an acid chloride, and an acid anhydride.

3. The method of claim 1 , wherein the acid is selected from the group consisting of an acidic ion exchange resin, a sulfonic acid, sulfamic acid, and hydrochloric acid.

4. The method of claim 1 , wherein R 2a has the formula —(CHX)R 2b , wherein X is halogen and R 2b is C 1-17 alkyl.

5. The method of claim 1 , wherein R 2a is chloromethyl.

6. The method of claim 1 , wherein the compound of formula IIa is 5-(chloromethyl)furfural.

7. The method of claim 1 , wherein the compound of formula I is 2,5-dimethylfuran.

8. The method of claim 1 , wherein the hydrogen source is hydrogen gas.

9. The method of claim 1 , wherein the catalyst is a transition metal-based catalyst.

10. The method of claim 9 , wherein the catalyst is palladium on carbon.

11. The method of claim 1 , comprising:
forming the first reaction mixture comprising acetic anhydride, an acidic ion exchange resin, and the compound of formula IIa having the structure:

under conditions sufficient to form the compound of formula IIb having the structure:

and
forming the reaction mixture comprising palladium on carbon, hydrogen gas, and the compound of formula IIb, under conditions sufficient to form the compound of formula I having the structure:

12. The method of claim 1 , comprising:
forming the first reaction mixture comprising n-butanol, hydrochloric acid, and the compound of formula IIa having the structure:

under conditions sufficient to form the compound of formula IIb having the structure:

and
forming the reaction mixture comprising palladium on carbon, hydrogen gas, and the compound of formula IIb under conditions sufficient to form the compound of formula I having the structure:

13. The method of claim 1 , comprising:
forming the first reaction mixture comprising ethanol, hydrochloric acid, and the compound of formula IIa having the structure:

under conditions sufficient to form the compound of formula IIb having the structure:

and
forming the reaction mixture comprising palladium on carbon, hydrogen gas, and the compound of formula IIb under conditions sufficient to form the compound of formula I having the structure:

14. The method of claim 1 , wherein the reaction mixture comprising the catalyst, the hydrogen source, and the compound of formula II further comprises N,N-dimethylformamide.

15. The method of any of claim 14 , wherein the reaction mixture comprising the catalyst, the hydrogen source, the compound of formula II, and N,N-dimethylformamide further comprises acetic acid.

16. The method of claim 1 , wherein the reaction mixture comprising the catalyst, the hydrogen source, and the compound of formula II further comprises pentane.

Assignees

• Univ California

Inventors

• Mascal Mark
• Dutta Saikat

Classifications

• C07D307/36 Primary

  with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms · CPC title