Rigidized oxazole dyes
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsJohn H. Hall, Ronald A. Henry, Richard A. Hollins
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Abstract
The quaternary salts of rigidized 1,3-oxazole compounds of the formula: ##STR1## where R is either H or CH.sub.3 O. The compounds are produced in a modif Robinson-Gabriel synthesis of oxazoles. These dyes are used in solution with non-interfering polar solvents, such as ethanol and H.sub.2 O, to form lasing media useful in dye lasers.
Claims6
As a composition of matter 2-(4-N-methylpyridinium)-4,5-dihydronaphtho [2,1-d]-1,3-oxazole p-toluenesulfonate.
As a composition of matter 2-(4-N-methylpyridinium)-4,5-dihydro6-methoxynaphtho[2,1-d]-1,3-oxazole p-toluenesulfonate.
A method for producing 2-(4-pyridyl)-4,5-dihydro-naphtho[2,1-d]-1,3-oxazole by a modified Robinson-Gabriel synthesis of oxazoles, the improvement comprising the steps:
- mixing the isonicotinamide of 2-amide-1-tetralone with phosphorus oxychloride;
- refluxing said mixture;
- removing the excess reagent and isolating a residue;
- forming a solution of said residue, ethanol and water;
- making said solution said residue, ethanol and water;
- making said solution basic by adding a hydroxide;
- and
- precipitating the oxazole by cooling said basic solution and then removing said oxazole.
A method of preparing the quaternary salt 2-(4-N-methyl-2-pyridinium)-4,5-dihydro-naphtho[2,1-d]-1,3-oxazole p-toluenesulfonate from 2-(4-pyridyl)-4,5-dihydro-naphtho [2,1-d]-1,3-oxazole comprising the steps:
- dissolving said oxazole in a solution of dichloroethane and methyl p-toluenesulfonate;
- refluxing said solution;
- and
- crystallizing the product by cooling said solution.
A method for producing 2-(4-pyridyl)-4,5-dihydro-6-methoxynaphtho[2,1-d]-1,3-oxazole by a modified Robinson-Gabriel synthesis of oxazoles, the improvement comprising the steps:
- mixing the isonicotinamide of 6-methoxy-2-amino-1-tetralone with phosphorus oxychloride;
- refluxing said mixture;
- removing the excess reagent and isolating a residue;
- forming a solution of basic by adding a hydroxide;
- and
- precipitating the oxazole by cooling said basic solution and then removing said oxazole.
A method for producing the quaternary salt 2-(4-N-methylpyridinium)-4,5-dihydro-6-methoxynaphtho[2,1-d]1,3-oxazole p-toluenesulfonate from 2-(4-pyridyl)-4,5-dihydro-6-methoxynaphtho[2,1-d]-1,3-oxazole comprising the steps:
- dissolving said oxazole in a solution of dichloroethane;
- and methyl p-toluenesulfonate;
- refluxing said solution;
- and
- crystallizing the product by cooling said solution.
Dependencies are inferred from the claim text.