85335-04-2Relevant articles and documents
The Reaction of Piperazine-2,5-dione with 2-Formylbenzoic Acid
Baron, Margaret L.,Rae, Ian D.,Simmonds, Peta M.
, p. 2567 - 2569 (2007/10/02)
Reaction of piperazine-2,5-dione with 2-formylbenzoic acid in the presence of triethylamine gives three products: 1-(3'-oxo-1',3'-dihydroisobenzofuran-1'-yl)piperazine-2,5-dione, its 1,4-bis analogue which had previously been identified as the 3,6-compound, and 2,2'-3,6-dioxopiperazine-2,5-diylidenebis(methylidyne)bis(benzoic acid).The latter compound is shown by 1H and 13C n.m.r. spectroscopy to be the Z,Z isomer.