Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others. Keywords: alkenylation; dibenzo[d,f][1,3]diazepin-6(7H)-one; indolin-2-one; ketene dithioacetal

• was characterized as 1-aryl-3-sec-amino-5H-dibenzo[d,f][1,3]diazepin-6(7H)-one 10. The formation of 10 is possible only if the reaction is initiated with Michael addition of indolin-2-one at C6 not at C4, due to the presence of the secondary amino group, which reduces its electrophilicity. Thus

• Perkin-Elmer AX-1 spectrophotometer in KBr disc and are reported in wave number (cm−1). ESIMS spectrometers were used for mass spectra analysis. Synthesis of 1-phenyl-3-(methylthio)-5H-dibenzo[d,f][1,3]diazepin-6(7H)-one (5) A mixture of indoline-2-one (4, 1.1 mmol) and 2-pyranone (3, 1.0 mmol) and t