?2-Thiopheneacetic acid (CAS NO.1918-77-0), its Synonyms are 2-Thienylacetic acid ; Thiopheneacetic acid ; 2-(2-Thienyl)aceticacid ; 2-(Thiophen-2-yl)acetic acid ; Thiophen-2-ylacetic acid ; 2-Thienylethanoicacid .