Synthesis of Azalurenone Alkaloids by Pd- mediated Intramolecular Oxidative Cyclisation Protocol

In this paper we present the synthesis of different substituted azafluorenone via oxidative intra-molecular Heck cyclization protocol. The Heck precursor alcohols were synthesised via reaction of the Grignard reagents of corresponding iodides upon 2-bromopyridine-3-carboxaldehyde The Grignard reagents were easily prepared from fresh magnesium turnings activated by pinch of iodine and their corresponding halides (iodide or bromide) in refluxing dry ether medium. Then these freshly prepared Grignard reagents were added drop wise into an ice-cold ethereal solution of 2-bromoprydine-3-carboxaldehyde , which gave our desired Heck precursor alcohols in quantitative yields