초록 ▼

Methods of preparing bis-(1(2)H-tetrazol-5-yl)-amine (BTA) having improved physical and chemical characteristics are disclosed. In the process, a dicyanamide salt and an azide salt are reacted at high temperature in the presence of an acid reagent. Best yields are obtained when the reaction is allow

Methods of preparing bis-(1(2)H-tetrazol-5-yl)-amine (BTA) having improved physical and chemical characteristics are disclosed. In the process, a dicyanamide salt and an azide salt are reacted at high temperature in the presence of an acid reagent. Best yields are obtained when the reaction is allowed to proceed for approximately 48 hours. The dicyanamide salt is preferably present in a stoichiometric excess. The acid reagent has a pKa in the range from about 3 to about 9. The reaction mixture is acidified to a pH less than 3. Several variations of the acidification step permit control of particle size and morphology. Small, rounded particles are prepared by rapidly cooling the hot crude reaction product coincidentally with acidification. This is preferably accomplished by adding the hot crude reaction product directly to cold concentrated acid. The precipitated particles are isolated to yield BTA.

대표청구항 ▼

A process for preparing bis-(1(2)H-tetrazol-5-yl)-amine comprising the steps of: (a) combining an azide salt, a dicyanamide salt, and an acid reagent in water, such that at least one mole of the dicyanamide salt is present for every two moles of the azide salt and at least one mole of the acid reage

A process for preparing bis-(1(2)H-tetrazol-5-yl)-amine comprising the steps of: (a) combining an azide salt, a dicyanamide salt, and an acid reagent in water, such that at least one mole of the dicyanamide salt is present for every two moles of the azide salt and at least one mole of the acid reagent is present for each mole of the azide salt and wherein the acid reagent has a pKa in the range from about 3 to about 9, wherein the combined ingredients form a reaction solution; (b) heating the reaction solution to a temperature greater than 65°C., wherein the combining step occurs either prior to or during said heating step; (c) acidifying the reaction solution with a strong acid after the reaction is substantially complete to protonate the bis-(1(2)H-tetrazol-5-yl)-amine product; and (d) isolating the bis-(1(2)H-tetrazol-5-yl)-amine product.