Pagoclone

Pagoclone and pazinaclone both contain an isoindolone structural motif Reaction of phthalic anhydride [85-44-9] (1) with 2-Amino-7-chloro-1,8-naphthyridine [15944-33-9] (2) with leads to the corresponding phthalimide. Selective reduction of one of the imide carbonyl groups give the corresponding alcohol, 2-(7-chloro-1,8-naphthyridin-2-yl)-3-hydroxyisoindolin-1-one [55112-38-4] (3). Reaction with the carbanion from Ethyl 5-methyl-3-oxohexanoate [57689-16-4] (4) leads to the product from the displacement of the hydroxyl group; 'this too may proceed via the acrylate obtained from aldol reaction of the ring opened imidal'. The product of this step is Ethyl 2-[2-(7-chloro-1,8-naphthyridin-2-yl)-3-oxo-1-isoindolinyl]-6-methyl-3-oxoheptanoate, PC9891305 (5). == See also ==