Organic azides were prepared from primary amines in high yields by metal-free diazo transfer with 2-azido-1,3-dimeth-

Organic azides were prepared from primary amines in high yields by a metal free diazo-transfer reaction using 2-azido-1,3-dimethylimidazolinium hexafluorophosphate (ADMP), which is safe and stable crystalline. The choice of base was important in the diazo-transfer reaction. In general, 4-(N,N-dimethyl)aminopyridine (DMAP) was efficient, but a stronger base such as alkylamine or DBU was more appropriate for the reaction of nucleophilic primary amines. X-ray single crystal structural analysis and geometry optimization using density functional theory (B3LYP/6-31G**) were conducted to study the ADMP structure, and the diazo-transfer reaction mechanism was explained with the help of the results of these analyses.

Direct synthesis of organic azides from alcohols was developed. Azide transfer of 2-azido-1,3-dimethylimidazolinium hexafluorophosphate (ADMP) to alcohols proceeds to give the corresponding azides under mild reaction conditions, which were easily isolated because the byproducts are highly soluble in water.

Direct Synthesis of Organic Azides from Alcohols Using 2-Azido-1,3-dimethylimidazolinium Hexafluorophosphate. -Azide transfer of the title reagent to alcohols proceeds under mild conditions which have to be slightly changed depending on the substrate. The azide products are easily isolated since the by-products are highly soluble in water. -(KITAMURA*, M.; KOGA, T.; YANO, M.; OKAUCHI, T.; Synlett 2012, 9, 1335-1338, http://dx.doi.org/10.1055/s-0031-1290958 ; Dep. Appl.

Many heavy-duty commercial vehicles are now equipped with urea-selective catalytic reduction (SCR) systems, which can reduce NO x emissions sufficiently to meet the requirements of legislation such as Japan's New Long-term Diesel Emissions Regulations. However, in order to meet even stricter exhaust emissions regulations (and fuel consumption standards) due to be imposed in many parts of the world in the near future, urea-SCR systems with greater catalytic efficiency combined with diesel particulate filters (DPFs) will be needed. Therefore, in the study presented here the scope for enhancing the efficiency of a urea-SCR system was explored by optimizing the urea dosing system and injection strategies, and the gas flow in the exhaust pipe. However, since improving the catalysis parameters could have the greatest overall effect on conversion efficiency, work focused on modifying the catalyst materials to increase their adsorption capacity for the NH 3 reducing agent, and thus increase the collision frequency between NO x and NH 3 absorbed on the surface of the catalyst. In addition, the oxidation parameters of the oxidation catalyst were optimized, which enhanced the NO x conversion efficiency of the system, not only in a steady cycle but also in a transient cycle. Following these adjustments, a DPF-plus-SCR system with the new catalytic material delivered 90 per cent conversions of NO x and particulate matter to N 2 and CO 2 respectively, in the JE05 test cycle.In addition, a new concept, a miniaturized 'urea-SCR with DPF function system' was proposed and tested, which delivered 90 per cent NO x conversion rates and 90 per cent reductions in particulate matter emissions in the JE05 test cycle.