Novel synthesis of N ‐{6‐aryl‐4‐[( E )‐2‐furylmethylene]‐1,2,3,4‐tetrahydro‐3‐oxopyridazin‐1 ‐ylcarbonyl}‐ p ‐toluenesulfonamides and N ‐{5‐[( E )‐1‐aroylmethyl‐2‐(2‐furyl) vinyl]‐1,3,4‐oxadiazol‐2‐yl} ‐ p ‐toluenesulfonamides

Novel N ‐{6‐aryl‐4‐[( E )‐2‐furylmethylene]‐1,2,3,4‐tetrahydro‐3‐oxopyridazin‐1 ‐ylcarbonyl}‐ p ‐toluene‐sulfonamides 4a‐d were prepared by the reaction of ( E )‐2‐aroylmethyl‐3‐(2‐furyl) acrylohydrazides 2a‐d with tosylisocyanate. This has been shown to occur by initial formation of ( E )‐2‐aroylmethyl‐3‐(2‐furyl)‐ N '‐(tosylaminocarbonyl) acrylohydrazides 3a‐d followed by acid catalyzed cyclization to afford N ‐{5‐[( E )‐1‐aroylmethyl‐2‐(2‐furyl)vinyl]‐1,3,4‐oxadiazol‐2‐yl}‐ p ‐toluenesulfonamides 5a‐d .