Efficient and convenient synthesis of spiroindolinone-quinazolines induced by stannous chloride

An efficient, convenient, one-pot synthesis of 1′H-spiro[indoline-3,2′-quinazoline]-2,4′(3′H)-dione derivatives was accomplished in good yields via the novel reductive cyclization of 2-nitrobenzamides and isatins mediated by SnCl2·2H2O system. A variety of substrates can participate in the process with good yields, making this methodology have broad applicability. The structure of compound 3c has been confirmed by X-ray diffraction analysis.