Methods for removing triazine from N-methylimidazole for synthesis of oligonucleotide

Patent metadata

Field	Value
Publication number	US-9556124-B2
Application number	US-201414471635-A
Country	US
Kind code	B2
Filing date	Aug 28, 2014
Priority date	Oct 31, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

Methods for removing 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine from a N-methylimidazole and methods for making oligonucleotides using N-methylimidazole are provided. In one embodiment, a method for removing 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine from a feedstock containing N-methylimidazole includes contacting the feedstock with small or medium pore molecular sieves. The small or medium pore molecular sieves adsorb 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine from the feedstock. The method further includes separating the small or medium pore molecular sieves from the feedstock.

First claim

What is claimed is:

1. A method for removing 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine from a feedstock containing N-methylimidazole, the method comprising:
contacting the feedstock with small or medium pore molecular sieves, wherein the small or medium pore molecular sieves adsorb 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine from the feedstock; and
separating the small or medium pore molecular sieves from the feedstock.

2. The method of claim 1 wherein contacting the feedstock with small or medium pore molecular sieves comprises contacting the feedstock with synthetic molecular sieves having a pore aperture size of no more than about 0.6 nm.

3. The method of claim 2 wherein contacting the feedstock with small or medium pore molecular sieves comprises contacting the feedstock with silicoaluminophosphate (SAPO) molecular sieves.

4. The method of claim 3 wherein contacting the feedstock with small or medium pore molecular sieves comprises contacting the feedstock with SAPO-34 molecular sieves.

5. The method of claim 1 wherein contacting the feedstock with small or medium pore molecular sieves comprises:
mixing the feedstock with the small or medium pore molecular sieves in a chamber,
heating the chamber to form a reflux of condensed vapor, and
returning the reflux to the chamber.

6. The method of claim 1 further comprising the step of heating the small or medium pore molecular sieves and the feedstock to the boiling point of the feedstock for at least about 3 minutes.

7. The method of claim 1 wherein separating the small or medium pore molecular sieves from the feedstock forms a supernatant containing the N-methylimidazole, and wherein the method further comprises fractionating the supernatant to obtain an N-methylimidazole product.

8. The method of claim 1 wherein the feedstock has a 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine concentration of about 200 parts per million (ppm) to about 1100 ppm, and wherein separating the small or medium pore molecular sieves from the feedstock comprises isolating a supernatant with a 1,3,5-trimethylhexahydro-1,3,5-triazine and N-methylenemethanamine concentration of about 0 ppm to about 20 ppm.

9. The method of claim 1 wherein contacting the feedstock with small or medium pore molecular sieves comprises contacting the small or medium pore molecular sieves with the feedstock in a ratio between about 0.5 grams (g) of the small or medium pore molecular sieves per 100 milliliters (ml) of feedstock to about 8 g of the small or medium pore molecular sieves per 100 ml of feedstock.

10. The method of claim 1 wherein contacting the feedstock with small or medium pore molecular sieves comprises contacting the small or medium pore molecular sieves with the feedstock in a ratio of about 2.5 grams (g) of the small or medium pore molecular sieves per 100 milliliters (ml) of feedstock.

Assignees

• Honeywell Int Inc

Inventors

• Mohan Venkatraman
• Lorenz Sandra M
• Gajda Gregory

Classifications

• C07D233/58 Primary

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

• C07H21/04

  with deoxyribosyl as saccharide radical · CPC title

• C07H1/00

  Processes for the preparation of sugar derivatives · CPC title