Anticoccidials. VI. An improved synthesis of 1,6-dihydro-6-oxo-2-pyrazinecarboxylic acid 4-oxide and some related derivatives and determination of anticoccidial activity.

Discovery and biological evaluation of potent, selective, orally bioavailable, pyrazine-based blockers of the Nav1.8 sodium channel with efficacy in a model of neuropathic pain

“…4-Oxo-2-pyrazinecarboxylate (2) was formed by oxidation of methyl pyrazinecarboxylate (1) with mCPBA. 30 N-Oxide 2 was then refluxed in thionyl chloride to afford the key intermediate 3. 31 The regiochemistry of 3 is consistent with literature precedence, 31 and was confirmed by an HMBC NMR experiment, which showed a long-range correlation between H5 and C3, indicating that the ester and chloro substitutions are at the 2-and 6-positions.…”

“…In vitro characterization of pyrazine Na v 1.8 channel blockers[26][27][28][29][30][31][32][33][34][35][36] …”

Structure–Activity Studies of Diazabicyclo[3.3.0]octane-Substituted Pyrazines and Pyridines as Potent α4β2 Nicotinic Acetylcholine Receptor Ligands

“…Methyl 6-chloro-2-pyrazinecarboxylate ( 43 ) − served as an excellent intermediate for exploration of 6-substituted 2-pyrazinecarboxamides and could be readily prepared in two steps on a multigram scale (Scheme ). 4-Oxo-2-pyrazinecarboxylate ( 42 ) was formed by oxidation of methyl pyrazinecarboxylate ( 41 ) with m CPBA .…”

“…The monosubstituted pyrazine 5 was prepared in a two-step procedure was formed by oxidation of methyl pyrazinecarboxylate (41) with mCPBA. 52 N-Oxide 42 was reacted in refluxing SOCl 2 to afford the key intermediate 43. 53 The regiochemistry of 43, which is consistent with literature precedence, 53 was also confirmed by an HMBC NMR experiment, which showed a longrange correlation between H5 and C3, indicating the ester and chloro substitutions are at the 2-and 6-positions.…”