BIS-(1(2) H-TETRAZOL-5-YL)-AMINE MONOHYDRATE SYNTHESIS AND REACTION INTERMEDIATE
The present invention provides Bis-(1(2)H-tetrazol-5-YL)-amine compound, and safe and inexpensive methods for producing high quality Bis-(1(2)H-tetrazol-5-YL)-amine compound. Also provided are Bis-(1(2)H-tetrazol-5-YL)-amine intermediates, and methods for their preparation. The process of preparing Bis-(1(2)H-tetrazol-5-YL)-amine intermediate substantially combines dicyanamide salt, azide salt, solvent and acid at 40-70 C temperature. The process of preparing Bis-(1(2)H-tetrazol-5-YL)-amine anhydride and/or Bis-(1(2)H-tetrazol-5-YL)-amine monohydrate comprises heating the intermediate described above at ≧75 C and adding a second acid.
1 . A process of preparing Bis-(1(2)H-tetrazol-5-YL)-amine intermediate characterized by combining dicyanamide salt, azide salt, solvent, and acid at 15-70 C temperature.
2 . The process of claim 1 wherein said acid is added over a 30 minute to 4 hour period at 15-70 C temperature to the mixture of dicyanamide salt and azide salt.
3 . The process of claim 1 wherein said azide salt and acid mixture are added to dicyanamide solution over a 30 minute to 4 hour period at 15-70 C temperature.
4 . The process of claim 1 wherein said temperature is maintained at less than 65 C for the entire process.
5 . The process of claim 1 wherein the mole ratio of azide salt to dicyanamide salt is 1.90-2.20 to 1.
6 . The process of claim 1 wherein the mole ratio of acid to dicyanamide salt is 1.0-2.0 to 1.
7 . The process of claim 1 wherein said dicyanamide salt is an alkaline metal salt or an alkaline earth metal salt.
8 . The process of claim 1 wherein said azide salt is an alkaline metal salt or an alkaline earth metal salt.
9 . The process of claim 1 wherein said solvent is water.
10 . The process of claim 1 wherein said solvent is a combination of water and another solvent selected from the group consisting of non-protonic polar solvent, N-substitution lactan solvent, alcohol, and ether.
11 . Bis-(1(2)H-tetrazol-5-YL)-amine intermediate produced by the method of claim 1 , wherein Bis-(1(2)H-tetrazol-5-YL)-amine is 5% or less.
12 . A process for making Bis-(1(2)H-tetrazol-5-YL)-amine anhydride or Bis-(1(2)H-tetrazol-5-YL)-amine monohydrate, comprising heating one or more intermediates at 75 C or higher, and adding a second acid.
13 . The process of claim 12 wherein said intermediate is treated at 75 C or higher for 10-30 hours.
14 . The process of claim 12 wherein said second acid is added during the heating of one or more intermediates at 75 C or higher.
15 . The process of claim 12 wherein said controlled high temperature during addition of the second acid produces anhydrate or monohydrate compound selectively.
16 . The process of claim 15 wherein the temperature when adding a second acid at less than 70 C, can produce Bis-(1(2)H-tetrazol-5-YL)-amine monohydrate compound selectively.
17 . The process of claim 15 wherein the temperature when adding second acid at 70 C or more can produce Bis-(1(2)H-tetrazol-5-YL)-amine anhydride compound selectively.
18 . The process of claim 12 wherein the period of time for adding acid is 2-12 hours.
19 . The process of claim 12 wherein the second acid is added until the mixture becomes pH 3.
20 . At least one of Bis-(1(2)H-tetrazol-5-YL)-amine anhydride and Bis-(1(2)H-tetrazol-5-YL)-amine monohydrate compound produced by the process of claim 12 .
21 . The process of preparing Bis-(1(2)H-tetrazol-5-YL)-amine salt comprising adding amine to at least one of Bis-(1(2)H-tetrazol-5-YL)-amine anhydride and Bis-(1(2)H-tetrazol-5-YL)-amine monohydrate produced by claim 20 .
22 . Bis-(1(2)H-tetrazol-5-YL)-amine salt produced by the process of claim 21 .