Synthesis of pyrazolo[1,5-alpha]pyrimidinone regioisomers.
This work describes two distinct routes to prepare pyrazolo[1,5-alpha]pyrimidin-7-ones and two distinct routes to prepare pyrazolo[1,5-alpha]pyrimidin-5-ones. Use of 1,3-dimethyluracil as the electrophile in the preparation of the pyrimidin-5-one regioisomer represents a correction of previously reported results. Also, a novel reaction to prepare this isomer was identified and the reaction mechanism elucidated. This work provides the experimentalist with complimentary synthetic pathways that afford either the pyrimidin-7-one or the pyrimidin-5-one regioisomer.
Gavrin
Lori K
LK
Department of Exploratory Medicinal Chemistry and Chemical Technologies, Wyeth Research, 200 CambridgePark Drive, Cambridge, Massachusetts 02140, USA. gavrinl@wyeth.com
Lee
Arthur
A
Provencher
Brian A
BA
Massefski
Walter W
WW
Huhn
Stephen D
SD
Ciszewski
Gregory M
GM
Cole
Derek C
DC
McKew
John C
JC
D000893:Anti-Inflammatory Agents / Q000138:chemical synthesis*; D007536:Isomerism; D008956:Models, Chemical; D011720:Pyrazoles / Q000737:chemistry*; D011744:Pyrimidinones / Q000737:chemistry*; D012556:Schistosomicides / Q000138:chemical synthesis; D014498:Uracil / Q000031:analogs & derivatives / Q000737:chemistry
D000893:Anti-Inflammatory Agents; D011720:Pyrazoles; D011744:Pyrimidinones; D012556:Schistosomicides; D014498:Uracil; C002451:1,3-dimethyluracil