6-[(2,5-Dimethoxyphenyl)methyl]-5-methylpyrido[2,3-d]pyrimidine-2,4-diamine mono(2-hydroxyethanesulfonate) 72732-56-0 79483-69-5 (ISETHIONATE) AIDS-000292 AIDS000292 BW 301U NSC351521 (ISETHIONATE) PTX Piritrexim Piritrexim Isethionate