4-methyl-amino-antipyrine

Clinical use Metamizol is the water-soluble sodium sulfonate of amidopyrine. After oral administration it is rapidly hydrolyzed to the active 4-methyl-amino-antipyrine and metabolized to various metabolites (Levy et al., 1995 scheme 47). Metamizol has strong analgesic, spasmolytic and antipyretic action, but no anti-inflammatory properties. The exact mechanism of action is unknown but may include inhibition of prostaglandin synthesis. Inhibition of both COX isoenzymes has been demonstrated, although only in extremely high concentrations, thus questioning the relevance of this activity. 

The active metabolite 4-methyl-amino-antipyrine reaches peak plasma concentrations 1.2 to 2 h after oral administration and is further metabolised with a mean elimination half-life of 2.6 to 3.5 h. Of the four main metabolites about 60% are excreted in the urine. Protein binding of these metabolites is less than 60% (Levy et al. 1995). 

Dipyrone, also known as metamizole sodium. Analgin, Novalgin or Melubrin, displays the highest efiScacy among antipyretic analgesics and is effective in visceral pain associated with smooth muscle spasm. It is rapidly absorbed when administered orally or via the rectal route. It is water soluble and is also available for intravenous administration. Dipyrone is a prodrug which, after oral administration, is rapidly hydrolysed in the gastric environment to its major metabolite 4-methyl-amino-antipyrine (MAA) and... 

Methyl-amino-antipyrine, a main metabolite of metamizole, cause a significant increase if the sample is taken within 30 minutes after i.v. administration of the drug. In urine samples this interference could not be found. 

Nitriloacetic acid reacts with vanadium-(m). -(iv), or -(v) oxides to form oxovanadatranetrionic acid (38). The crystal structure of [VO(CjQHgNO)2] (CjgHgNOH = 2-methyl-8-quinolinol) has shown that the vanadium atom has a five-co-ordinate trigonal-bipyramidal environment, with three oxygen atoms in the equatorial plane and the two nitrogen atoms of the bidentate ligand in the apical positions. The optimum conditions for the formation of a 1 2 2 vanadium(iv)-morin-4-aminoantipyrine system have been described as pH 5, a tenfold excess of morin (39), and a 3300-fold excess of 4-amino-antipyrine. ... 

A few other methods of preparing 4-amino-3-pyrazolin-5-ones have been reported but none has been used extensively. Methylation of the N-2 of 2-pyrazolin-5-ones, the classical 3-pyrazolin-5-one synthesis, has been reported only once.536 Emerson and co-workers426 have hydrolyzed iminotoluquinone substituted by antipyrine to give the... 

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