Facile synthesis of 3H,3′H-spiro[benzofuran-2,1′-isoindole]-3,3′-diones using monobromomalononitrile (MBM) as an efficient organo-brominating agent
摘要:
An efficient methodology for the synthesis of 3H,3'H-spiro[benzofuran-2,1'-isoindole]-3,3'-diones has been developed where monobromomalononitrile (MBM) has been employed as a non-hazardous brominating agent under ambient reaction condition. The intrinsic advantages of the methodology are the utilization of simple and easily available starting materials and non-toxic reagents, operational simplicity, and good yields of the products with high atom-economy. (C) 2014 Elsevier Ltd. All rights reserved.
Silica sulfuric acid: an efficient reusable heterogeneous solid support for the synthesis of 3H,3′H-spiro[benzofuran-2,1′isobenzofuran]-3,3′-diones under solvent-free condition
A highly efficient protocol for the library synthesis of biologically important 3H,3'H-spiro[benzofuran-2,1'isobenzofuran]-3,3'-diones has been developed by employing silica sulfuric acid (SSA) as solid acid support under solvent-free condition. The dual characteristics of SSA, as an activating agent as well as oxidizing agent, have been well exposed in these syntheses. The intrinsic advantages of the methodology are the use of solvent-free reaction condition without using any toxic reagents or metal catalyst, operational simplicity, recyclability of the solid support, good availability of the starting materials, and excellent yields which make the method attractive, economic, and 'benign by design'. (C) 2014 Elsevier Ltd. All rights reserved.