A new synthesis for the title compound that gives an 80% overall yield was developed. Treatment of triaminoguanidine monohydrochloride (1) with 2,4‐pentanedione (2) gave 3,6‐bis(3,5‐dimethylpyrazol‐1‐yl)‐1,2‐dihydro‐1,2,4,5‐tetrazine (3) in 80–85% yield. Oxidation of 3 with nitric oxide or nitrogen dioxide to 3,6‐bis(3,5‐dimethyylpyrazol‐1‐yl)‐1,2,4,5‐tetrazine (4) followed by ammonolysis of 4 gave 3,6‐diamino‐1,2,4,5‐tetrazine (5) in guantitatively yields.

The diffusional model for solvent removal from porous rubber particles in aqueous slurries that was derived from batch laboratory experiments gives a good correlation of data obtained in a commercial-scale, continuous-flow vessel. The model accounted for the effects of the major operating variables. Also, the value of the effective crumb radius, the only parameter in the model, was in reasonable agreement between the batch and continuous experiments.However, three simplifying assumptions were required for the analysis of the continuous flow data: (1) the crumb in the vessel is perfectly mixed; (2) the rubber concentration is the same in the vessel as in the feed; and (3) the crumb size does not affect R, the effective crumb radius for diffusion.Approximation of the crumb residence time distribution by an exponential probably does not lead to serious error.Literature Cited

Acid dewpoints were calculated from SO2-to-SO3 conversion in gas turbine exhaust. These data can be used as guidelines in setting feedwater temperatures in combined-cycle systems. Accurate settings can prevent corrosion of heat-exchanger (boiler) tubes, thus extending their life time. This study was done using gas turbine engines and a laboratory generator set. The units burned marine diesel or diesel No. 2 fuel with sulfur contents up to 1.3 percent. The exhaust from these systems contained an excess of 20 percent oxygen, and 3–10 percent water vapor. Exhaust temperatures ranged from 728 to 893 K (455 to 620°C).

Efficient, convenient, and direct alkylation of diethyl malonate, acetylacetone, ethyl acetoacetate, ethyl cyanoacetate, and related compounds has been effected in a one-stage process involving the free-radical-initiated addition of the reactive methylene compound to a suitable olefin.RADICAL-INDUCED chain addition reactions of olefins have been known since 1937, when it was first postulated 192 that anti-Markownikoff addition of hydrogen bromide to terminal olefins proceeded as follows (X = H, Y = Br) :

A series of explosive compositions was treated with commercially available oils. Samples were analyzed by differential thermal analysis, accelerating rate calorimetry, and drop‐weight impact test. Results were compared with those of the untreated compositions. Some systems showed definite incompatibilities. These data are beneficial to individuals who must select safing fluids for desensitizing explosives contained in assemblies that are damaged as a result of an accident. This is especially true where broken pieces of high explosives might rub together or against metal surfaces, thus causing increased hazards during handling operations.