[(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)methylamino]methanesulphonic acid

ChEBI: A pyrazole that is antiipyrine substituted at C-4 by a methyl(sulfomethyl)amino group, the sodium salt of which, metamizole sodium, was widely used as a powerful analgesic and antipyretic, but withdrawn from many markets from the 1970s due to a risk of cau ing risk of causing agranulocytosis.