3,5-Dimethyl-1-(1,1-dioxotetrahydrothiophen-3-yl)-1H-pyrazole-4-carboxylic acid1-(1,1-dioxidotetrahydrothiophen-3-yl)-3,5-dimethyl-1H-pyrazole-4-carboxylic acid1-(1,1-Dioxo-tetrahydro-1lambda*6*-thiophen-3-yl)-3,5-dimethyl-1H-pyrazole-4-carboxylic acid