|
|
Patent Number: |
7495106 |
|
|
Case ID: |
0 |
|
|
Patent Title:
|
O-aminophenol-containing AB-monomer for heterocyclic rigid-rod polymers
|
|
|
Status: |
ACTIVE |
|
|
Status Date: |
2/3/2010 1:55:45 PM |
|
|
Issue Date:
|
2/24/2009 |
|
|
Filed Date:
|
11/29/2007 |
|
|
Serial #:
|
1/998,862 |
|
|
Assignee Name:
|
United States of America as represented by the Secretary of the Air Force
(Washington,
DC)
|
|
|
Inventor(s):
|
Tan, Loon-Seng , Kannan, Ramamurthi , Spain, Jim C. , Nadeau, Lloyd J. |
|
|
Lab Name: |
Materials & Manufacturing Directorate |
|
|
Location: |
Building 653, Room 406
Wright-Patterson AFB, OH 45433-7734 |
|
|
Contact: |
Contact Lab About This Patent |
|
|
|
|
BACKGROUND OF THE INVENTION
The present invention relates to heterocyclic monomers, particularly to o-amino-hydroxy-benzothiazole-benzoic acid and a new enzymatic process to synthesize it from the corresponding nitro-benzothiazole-benzoic acid compound.
4,6-Diaminoresorcinol and 2,5-diamino-1,4-benzenedithiol (usually stored as dihydrochloride salts) are key co-monomers for the synthesis of high-strength-high-modulus, thermally resistant rigid-rod poly(p-phenylenebenzobisoxazole) (PBO) and
poly(p-phenylenebenzobisthiazole (PBT) polymers for lightweight structural, nonlinear optical and electronic applications.
##STR00002##
More recently, PBO and PBT have been considered for use in the proton-exchange membranes of fuel cells. While an AB-monomer 4-[5-amino-6-hydroxybenzoxazol-2-yl]benzoic acid has been prepared and utilized in the synthesis of the correspond PBO
polymer, the analogous AB-monomer for PBT, namely, 4-[5-amino-6-mercaptobenzothiazol-2-yl]be . . . . More |
|
|
|
|
A novel o-aminophenol-carboxylic AB-monomer with the following chemical
structure: ##STR00001## for synthesizing new rigid-rod
polybenzobisazoles was prepared from the corresponding
nitrobenzothiazolecarboxylic acid via an enzymatic process.
|
|
|
|
|
We claim:
1. 2-(4-Carboxyphenyl)-6-nitrobenzothiazole having the chemical structure: ##STR00004##
2. 4-(6-Amino-5-hydroxybenzothiazol-2-yl)benzoic acid having the chemical structure: ##STR00005##
3. An enzymatic process for synthesizing the 4-(6-amino-5-hydroxybenzothiazol-2-yl)benzoic acid of claim 2, said process comprising the steps of: a.) providing a 2-(4-carboxyphenyl)-6-nitrobenzothiazole and a recombinant E. coli JS995 strain
that expresses both nitroreductase and mutase activities; b) incubating said recombinant E. coli strain with said 2-(4-carboxyphenyl)-6-nitrobenzothiazole; c) converting said 2-(4-carboxyphenyl)-6-nitrobenzothiazole to said
4-(6-amino-5-hydroxybenzothiazol-2-yl)benzoic acid by said recombinant E. coli JS995 strain; and d) recovering a fraction containing said 4-(6-amino-5-hydroxybenzothiazol-2-yl)benzoic acid. |
|
|
|
|
Print This Page
