A novel series of cis-2-azetidinones 2(a-c ) was carried out by the cyclo addition reaction of imine 1(a-c ) and acyl chloride in dry dichloromethane at 0-5 oC using triphenylamine. The cyclo addition of the Schiff bases with chloroacetyl chloride resulted corresponding major product cis-2-azetidinone stereoisomers 2(a-c). The synthesized compounds were characterized by analytical and spectral (Infrared, 1H NMR, 13C NMR, and elemental analysis) data. Keywords: Benzothiazole, β-lactam, Schiff base, cis-2-azetidinone, Staudinger reaction Acknowledgements The authors would like to thank the Eskişehir Osmangazi University Scientific Research Projects Council for financial support (Project No: 2014/19A208). References • C. M. L. Delpiccolo, M. A. Fraga, E. G. Mata, J. Comb. Chem. 2003, 5, 208-210. DOI: 10.1021/cc020107d. • R. B. Pawar, V. V. Mulwad, Chem. Heterocycl. Compd. 2004, 40, 219-226. DOI: 10.1023/B:COHC.0000027896.38910.d1. • P. D. Mehta, N. P. S. Sengar, A. K. Pathak, Eur. J. Med. Chem. 2010, 45, 5541-5560. DOI: 10.1016/j.ejmech.2010.09.035. • G. S. Singh, B. J. Mmolotsi, Il Farmaco, 2005, 60, 727-730. DOI: 10.1016/j.farmac.2005.06.008. • C. D. Risi, G. P. Pollini, A. C. Veronese, V. Bertolasi, Tetrahedron Lett. 1999, 40, 6995-6998. DOI: 10.1016/S0040-4039(99)01421-5. • H. G. I. Georg: The Organic Chemistry of β-Lactams, Weinheim/VCH Publishers, New York, 1993, p. 295. DOI: 10.1002/ange.19941060738. • R. F. Abdulla, K. H. Fuhr, J. Med. Chem. 1975, 18, 625-627. DOI: 10.1021/jm00240a022. • W. Dürckheimer, J. Blumbach, R. Lattrell, K. H. Scheunemann, Angew. Chem. Int. Ed. Engl. 1985, 24, 180-202. DOI: 10.1002/anie.198501801. • P. D. Mehta, N. P. S. Sengar, A. K. Pathak, Eur. J. Med. Chem. 2010, 45, 5541-5560. DOI: 10.1016/j.ejmech.2010.09.035. • H. Staudinger, Justus Liebigs Ann. Chem. 1907, 356, 51-123. DOI: 10.1002/jlac.19073560106. • A. K. Bose, M. Jayaraman, A. Okawa, S. S. Bari, E. W. Robb, M. S. Manhas, Tetrahedron Lett. 1996, 37, 6989-6992. DOI: 10.1016/0040-4039(96)01571-7. • A. K. Bose, B. K. Banik, M. S. Manhas, Tetrahedron Lett. 1995, 36, 213-216. DOI: 10.1016/0040-4039(94)02225-Z. • A. Arrieta, B. Lecea, F. P. Cossio, J. Org. Chem. 1998, 63, 5869-5876. DOI: 10.1021/jo9804745. • P. Vicini, A. Geronikaki, M. Incerti, B. Busonera, G. Poni, C. A. Cabras, P. L. Colla, Bioorg. Med. Chem. 2003, 11, 4785-4789. DOI: 10.1016/S0968-0896(03)00493-0. • K. Mogilaiah, R. B. Rao, K. N. Reddy, Indian J. Chem. 1999, 38B, 818-822. • 16. I. Georg, V. T. G. I. Ravikumar, Ed. Verlag Chemie, 1993, 295- 368 New York, • L. Jiao, Y. Liang, J. Xu. J. Am. Chem. Soc. 2006, 128, 6060- 6069 • H. C. Sakarya, M. Yandımoğlu, Croat. Chem. Acta, 2018, 91, 533-541. DOI: 10.5562/cca3386. • D. A. Nelson, J. Org. Chem. 1972, 37, 1447-1449. DOI: 10.1021/jo00974a038. • K. D. Barrow, T. M. Spotswood, Tetrahedron Lett. 1965, 6, 3325-3335. DOI: 10.1016/S0040-4039(01)89203-0. • J. Decazes, J. L. Luche, H. B, Kagan, Tetrahedron Lett. 1970, 11, 3665-3668. DOI: 10.1016/S0040-4039(01)98556-9. • D. A. Nelson, Tetrahedron Lett. 1971, 12, 2543-2546. DOI: 10.1016/S0040-4039(01)96914-X.