Indole Grignard reagents with aldehydes

This new indole ring synthesis should find utility for the preparation of 2-aryUndoles with electron-withdrawing substituents in the indole ring. Furthermore, as we see in equations 1-3, the bromine atom is impervious to attack by the Grignard reagent. The starting ortfto-nitrostilbenes were prepared in the standard fashion from the appropriate ortho-nitrotoluene and aryl aldehyde with piperidine as base. 

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