924897-89-2Relevant academic research and scientific papers
Preparation of 4,5-diamino-1-(substituted)-pyrazole and acid addition salts thereof
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Page/Page column 5, (2010/11/25)
Disclosed is an improved process for the preparation of 4,5-diamino-1-(substituted)pyrazoles and acid addition salts thereof by coupling the corresponding 5-amino-1-(substituted)pyrazole with an aromatic diazonium compound to produce an intermediate azo compound and contacting the intermediate azo compound with hydrogen in the presence of a hydrogenation catalyst to produce 4,5-diamino-1-(substituted)pyrazoles. Also disclosed is a decarboxylation process for the preparation of a 5-amino-1-(substituted)pyrazole by heating a solution comprising a 5-amino-4-carboxy-1-(substituted)pyrazole, an inorganic acid and an inert solvent.
