A new procedure has been developed for the synthesis of indomethacin by the Fischer reaction, based on the acylation of sodium 2-(4-methoxyphenyl)-1- hydrazosulfonate with 4-chlorobenzoyl chloride and subsequent interaction with levulinic acid in the presence of formic acid. 2005 Springer Science+Business Media, Inc.
Synthetic Route to Phenyl Diazenes and Pyridazinium Salts from Phenylazosulfonates
The synthesis of pyridazinium salts was achieved from readily available phenylazosulfonates in a single reaction step. The reaction proceeds via the formation of short-lived phenyldiazenes, which-owing to the strongly acidic conditions-are partially proto
Gradl, Susanne,K?ckenberger, Johannes,Oppl, Janina,Schiller, Martin,Heinrich, Markus R.