ORGN 651 |
During our medicinal research program on 5-alkoxy or 5-amino pyrido[4,3-d]pyrimidin-4(3H)-ones, we developed a concise synthesis of 5-chloropyrido[4,3-d]pyrimidin-4(3H)-one (1) from a commonly used starting material 4-maino-2-chloropyridine (2). The key intermediate tert-butyl 4-(tert-butoxycarbonylamino)-2-chloronicotinate (3) was obtained as the exclusive product without its regioisomer through a unique rearrangement. Pyridopyrimidinone 1 was prepared in gram scale in overall yield 60% with only one column chromatography for this 5 steps synthesis. |
Heterocycles and Aromatics, Asymmetric Reactions and Syntheses and Total Synthesis of Complex Molecules
7:00 PM-9:00 PM, Wednesday, August 19, 2009 Walter E. Washington Convention Center -- Ballroom C, Poster
Division of Organic Chemistry |