Microwave mediated synthesis of spiro-(indoline-isoxazolidines):: mechanistic study and biological activity evaluation

Regioisomeric spiro-(indoline-isoxazolidines) have been synthesized in moderate yields by the cycloaddition reaction between ethyl (3-indolylidene)acetate and various Substituted alpha,N-diplienylnitrones, using environmentally benign microwave technology. A novel concerted reaction mechanism is described that explains the preferential formation of the regioisomeric spiro-(indoline-isoxazolidine) analogs 6 over 5. These compounds were screened for anti-mycobacterial and anti-invasive activities against tumor cells. (c) 2005 Elsevier Ltd. All rights reserved.