1. (a) Dhara, M. G.; De, S. K.; Mallik, A. K. Tetrahedron Lett. 1996, 37, 8001.
2. (b) Mallik, A. K.; Dhara, M. G.; Chattopadhyay, F. Indian J. Chem. 1998, 37B, 1164.
3. (c) Dey, S. P.; Mallik, A. K. Indian J. Chem. 1999, 38B, 400;
4. (d) Mallik, A. K.; Chattopadhyay, F. Indian J. Chem. 1999, 38B, 889.
5. The 3-benzoylchromones 4a–d are known compounds.1d Selected data of 5: 5a mp 151–152°C. Anal.: found C, 77.41; H, 3.81; N, 5.40%; calcd for C16H9NO2 C, 77.72; H, 3.67; N, 5.66%. IR (ν, KBr, cm−1): 2210 (CN), 1645(CO). 1H NMR (300 MHz, CDCl3) δ 7.54 (1H, dt, J=7.6 and 0.9 Hz, H-6), 7.59–7.71 (4H, m, Ar-H), 7.80 (1H, ddd, J=7.6, 7.2 and 1.5 Hz, H-7), 8.11–8.15 (2H, m, H-2′,6′) and 8.29 (1H, dd, J=8.0 and 1.5 Hz, H-5). 13C NMR (75 MHz, CDCl3): δ 98.36 (C-3), 113.96 (CN), 118.28 (C-8), 122.03 (C-4a), 126.25 (C-6), 126.87 (C-5), 128.75 (C-3′,5′), 129.16 (C-2′,6′), 130.16 (C-1′), 133.34 (C-4′), 135.25 (C-7), 155.46 (C-8a), 170.84 (C-2) and 174.14 (C-4). EIMS: m/z 247(M+). Compound 5b: mp 169–170°C. Compound 5c: mp 206–207°C. Compound 5d: mp 202–203°C.