modafinil acid modafinil acid modafinil acid (code name crl-40467), also known as modafinilic acid or modafinil carboxylate, is one of the two major metabolites of modafinil – the other being modafinil sulfone. modafinil acid is also a metabolite of the modafinil prodrug, adrafinil, and the (r)-(–)-enantiomer is a metabolite of armodafinil, the (r)-(–)-enantiomer of modafinil. between 30 - 60% of modafinil is converted to modafinil acid and its half life is roughly half that of modafinil (about 7 hours). modafinil acid seems to be inactive, and similarly to modafinil sulfone, does not appear to contribute to the wakefulness-promoting/psychostimulant effects of modafinil. modafinil acid names preferred iupac name (diphenylmethanesulfinyl)acetic acid other names modafinilic acid; modafinil carboxylate; crl-40467 identifiers cas number 63547-24-0 y 3d model (jsmol) interactive image chemspider 2342211 echa infocard 100.219.633 pubchem cid 3085267 unii 54n37hn7n4 y comptox dashboard (epa) dtxsid60979768 inchi inchi=1s/c15h14o3s/c16-14(17)11-19(18)15(12-7-3-1-4-8-12)13-9-5-2-6-10-13/h1-10,15h,11h2,(h,16,17)key: qarqpiwtmbrjfx-uhfffaoysa-n smiles c1=cc=c(c=c1)c(c2=cc=cc=c2)s(=o)cc(=o)o properties chemical formula c15h14o3s molar mass 274.33 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references in the breakdown process of modafinil, modafinil is primarily hydrolyzed by an esterase or amidase enzyme into modafinil acid. the apparent clearance of modafinil acid is significantly higher than that of modafinil, following the hypothesis that metabolism increases the polarity and the clearance of modafinil.