Synthesis and optimization of 2-pyridin-3-yl-benzo[d][1,3]oxazin-4-one based inhibitors of human neutrophil elastase
摘要:
The hit-to-lead optimization of the HNE inhibitor 5-methyl-2-(2-phenoxy-pyridin-3-yl)-benzo[d][1,3]oxazin-4-one is described. A structure-activity relationship study that focused on the 5 and 7 benzoxazinone positions yielded the optimized 5-ethyl-7-methoxy-benzo[d][1,3]oxazin-4-one core structure. 2-[2-(4Methyl-piperazin-1-yl)-pyridin-3-yl] derivatives of this core were shown to yield HNE inhibitors of similar potency with significantly different stabilities in rat plasma. (C) 2009 Elsevier Ltd. All rights reserved.
Microwave-assisted synthesis of 2-aminonicotinic acids by reacting 2-chloronicotinic acid with amines
摘要:
2-(Methylamino)nicotinic acid was readily prepared in high yield by reacting 2-chloronicotinic acid with 40% aq MeNH2 under microwave irradiation either at 120 degrees for 2 h or at 140 degrees C for 1.5 h. Subsequently, we found that a range of 2-aminonicotinic acids could be obtained under microwave heating. The optimal reaction conditions involved the use of 3 equiv of amine, water as the solvent and heating at 200 degrees C for 2 h in the presence of diisopropylethylamine (3 equiv). (C) 2009 Elsevier Ltd. All rights reserved.