(4-(2,5-Dioxopyrrolidinyl)-2-butynyl)thiolanium perchlorate 1-(4-(2,5-Dioxo-1-pyrrolidinyl)-2-butynyl)tetrahydrothiophenium perchlorate 110826-59-0 Thiophenium, tetrahydro-1-(4-(2,5-dioxo-1-pyrrolidinyl)-2-butynyl)-, perchlorate