Preparation of benzotriazoles
AssigneeThe Sherwin-Williams Company
InventorsJohn W. Long, Lubomir Vacek
Life of this patent
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Abstract
This invention relates to a process for producing benzotriazoles which comprises effecting a mixture in an aqueous medium of at least one aromatic orthodiamine and one or more nitrites and heating the mixture to temperatures ranging up to about 350.degree. C. while maintaining pressures at levels sufficient to keep effective amounts of water present for the reaction.
Claims18
A process for producing aqueous metal salts of benzotriazoles consisting essentially of mixing in the presence of water reactive amounts of:
- (a) at least one aromatic orthodiamine having the structure:
- ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and selected from the group consisting of hydrogen, alkyl, alkoxy, aryl, aroxy, aralkyl, aralkoxy, alkaroxy, and halogen wherein aryl and "ar-" is defined as phenyl and wherein alkyl or "alk-" is defined as having 1-50 carbons;
- and
- (b) at least one alkali metal nitrite;
- and heating the aqueous mixture at temperatures ranging from about 100.degree. C. up to about 350.degree. C. and at pressures sufficient to maintain liquid water in the reaction.
A process for producing benzotriazoles consisting essentially of:
- (a) preparing an aqueous solution of a metal salt of benzotriazoles by mixing in the presence of water reactive amounts of:
- (i) at least one aromatic orthodiamine having the structure:
- ##STR3## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and selected from the group consisting of hydrogen, alkyl, alkoxy, aryl, aroxy, aralkyl, aralkoxy, alkaroxy, and halogen wherein aryl and "ar" is defined as phenyl and wherein alkyl or "alk." is defined as having 1-50 carbons;
- and
- (ii) at least one alkali metal nitrite;
- and heating the aqueous mixture at temperatures ranging from about 100.degree. C. up to about 350.degree. C. and at pressure sufficient to maintain liquid water in the reaction;
- and
- (b) adding acid to the aqueous solution of salts of benzotriazoles to lower the pH below 7 to produce free benzotriazoles;
- and
- (c) separating the free benzotriazole from the aqueous solution.
A process for producing aqueous metal salts of benzotriazoles which comprises mixing in the presence of water reactive amounts of:
- (a) at least one aromatic orthodiamine selected from the group consisting of 1,2-benzenediamine, 3-methyl-1,2-benzenediamine, and 4-methyl-1,2-benzenediamine;
- and
- (b) at least one alkali metal nitrite;
- and heating the aqueous mixture at temperatures ranging from about 100.degree. C. up to about 350.degree. C. and at pressures sufficient to maintain liquid water in the reaction.
A process for producing benzotriazoles which comprises:
- (a) preparing an aqueous solution of a metal salt of benzotriazoles by mixing in the presence of water reactive amounts of:
- (i) at least one aromatic orthodiamine selected from the group consisting of 1,2-benzenediamine, 3-methyl-1,2-benzenediamine, and 4-methyl-1,2-benzenediamine;
- and (ii) at least one alkali metal nitrite;
- and heating the aqueous mixture at temperatures ranging from about 100.degree. C. up to about 350.degree. C. and at pressures sufficient to maintain liquid water in the reaction;
- and
- (b) adding acid to the aqueous solution of salts of benzotriazoles to lower the pH below 7 to produce free benzotriazoles;
- and
- (c) separating the free benzotriazole from the aqueous solution.
Dependencies are inferred from the claim text.