1.1: SOCl2 / Heating 2.1: 2.12 g / sodium azide; tetrabutylammonium bromide / CH2Cl2; H2O / 2 h / 0 °C 3.1: toluene / 4 h / Heating 4.1: 1.28 g / aqueous HCl / 1.5 h / Heating 5.1: 89 percent / diethyl ether / 9 h / Heating 6.1: 9,10-dicyanoanthracene; biphenyl / acetonitrile / 1.5 h / Irradiation 6.2: 78 percent / silica gel / hexane; diethyl ether View Scheme