Synthesis of dibenzo[d,f]diazepinones and alkenylindolinones through ring transformation of 2H-pyran-2-one-3-carbonitriles by indolin-2-ones

First ever synthesis of functionalized 5,7-dihydro-6H-dibenzo[d,f][1,3]diazepin-6-ones (6, 9) has been developed through base induced ring transformation of 2H-pyran-2-one-3-carbonitriles with indolin-2-ones. A protocol for alkenylating indolin-2-ones by 2H-pyran-2-one-3-carbonitriles has also been developed to obtain 3-alkenylindolin-2-ones (11). The nature and behaviour of intermolecular interactions of these compounds are studied by single crystal-X-ray analysis and quantum chemical calculations.