01578nas a2200193   4500008004100000245018700041210006900228260000800297300001400305490000700319520079000326100002201116700002101138700002501159700002701184700001601211700002501227856013201252       2017                        eng d00aMicrowave-assisted synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition over a heterogeneous Cu-based catalyst: application to the preparation of N-13-labelled tetrazoles0 aMicrowaveassisted synthesis of 5substituted 1Htetrazoles via 32   cAUG  a8084-80910 v413 aThe [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of a new Cu-II catalyst in N-methyl-2-pyrrolidone (NMP) to give the corresponding 5-substituted 1H-tetrazoles. The desired tetrazoles were obtained in high yields within 3-30 min by employing controlled microwave heating. The reaction most probably proceeds through the activation of the nitrile groups by the Cu-II species, followed by a successive [3+2] cycloaddition with the sodium azide. The good performance of the catalyst enabled the preparation of selected tetrazoles labelled with the positron emitter nitrogen-13 even under conventional heating. The short reaction time, simple work-up procedure, and recyclability of the catalyst are advantages of the method reported here.1 aJoshi, Sameer, M.1 aMane, Rasika, B.1 aPulagam, Krishna, R.1 aGomez-Vallejo, Vanessa1 aLlop, Jordi1 aRode, Chandrashekhar  uhttps://library.ncl.res.in/content/microwave-assisted-synthesis-5-substituted-1h-tetrazoles-32-cycloaddition-over-heterogeneous