Process for the separation of racemic mixtures

• US 6,709,597 B1
• Filed: 11/29/2002
• Issued: 03/23/2004
• Est. Priority Date: 11/29/2002
• Status: Expired due to Fees

• Current Assignee: Council of Scientific & Industrial Research
• Original Assignee: Council of Scientific & Industrial Research
• Inventors: Choudary, Boyapati Manoranjan, Kalluri, Venkata Sri Ranganath, Mannepalli, Lakshmi Kantam
• Primary Examiner(s): Therkorn, Ernest G.
• Application Number:
  US10/306,743
• Time in Patent Office: 480 Days
• Field of Search: 210/635, 210/656, 210/660, 210/679, 210/198.2, 210/502.1, 521/99
• US Class Current: 210/635
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/28078 Pore diameter
• CPC Class Codes: B01J 20/2808 being less than 2 nm, i.e. micropores or nanopores
• CPC Class Codes: B01J 20/29 Chiral phases
• CPC Class Codes: B01J 20/3057 Use of a templating or imprinting material molecularly imprinted polymers B01J20/268; filling pores of a substrate or matrix followed by the removal of the substrate or matrix

Abstract

The present invention relates to a process for the separation of racemic mixtures comprising development of a denser molecular imprint on silica with a desired enantiomer by sol-gel protocol.

Claims

1. A process for the separation of racemic mixtures comprising developing a denser molecular imprint on silica with a desired enantiomer by sol-gel protocol, said sol-gel protocol comprising hydrolytic control polymerization of a silica source as the monomer and amino alkylsilane as a functional monomer in the presence of the desired enantiomer, capping of surface OH groups and desorption of encapsulated enantiomer from the silica, for the selective adsorption of 3-12% of the said enantiomer from the racemic mixture to effect resolution with high optical purity.

2. A process as claimed in claim 1 wherein the silica used is a nanoporous silica designed and developed with the defined shape and size to suit the desired enantiomer for resolution of the corresponding racemic mixture.

3. A process as claimed in claim 1 wherein the silica source used is tetraethylorthosilicate.

4. A process as claimed in claim 1 wherein the functional monomer comprises 3-amino alkyl triethoxysilane.

5. A process as claimed in claim 4 wherein the alkyl is selected from the group consisting of ethyl, propyl and butyl.

6. A process as claimed in claim 1 wherein the imprinted silica used for resolution is recycled for number of times.

7. A process as claimed in claim 1 wherein the ratio of imprint to the functional monomer molecule is from 1:

2 to 1;

5.

8. A process as claimed in claim 1 wherein the enantiomeric imprints used comprises Cbz protected (L)-alanine, (L)-phenylalanine and (L)-glutamic acid, and 1-mandelic acid.

9. A process as claimed in claim 1 wherein the percentage of imprint molecule to TEOS is from 2% to 10%.

10. A process as claimed in claim 1 wherein the solvent used for controlled hydrolysis is distilled water.

11. A process as claimed in claim 1 wherein capping of surface-OH group is carried out with an equimolar mixture of 1,1,1,3,3,3-hexamethyldisilazane and chlorotrimethyl silane.

12. A process as claimed in claim 1 wherein the source of silica used is tetraethylorthosilicate (“

TEOS”

) and 3-amino alkyl triethoxysilane as a functional monomer.

13. A process as claimed in claim 12 wherein the alkyl is selected from ethyl, propyl and butyl.

14. A process as claimed in claim 1 wherein the controlled hydrolysis is carried out from 0°

C. to 80°

C.