Solvent-free Synthesis of Quinolone Derivatives

Synthesis of Fused Pyrimidinone and Quinolone Derivatives in an Automated High-Temperature and High-Pressure Flow Reactor

“…Gould–Jacobs-type reactions involve the condensation of an arylamine with an alkoxymethylene compound followed by thermal cyclization to form the corresponding heterocyclic products (Scheme ). This transformation normally requires high temperatures and a short reaction time in order to avoid decomposition, thus making this ring-closing reaction an ideal protocol to adapt to high temperature synthesis in flow. Lengyel and co-workers have previously disclosed the synthesis of Gould–Jacobs- and Conrad–Limpach-type products in both an in-house built pyrolysis reactor and the X-Cube Flash, a high-temperature/high-pressure mesoreactor; while the successful adaptation of these thermal reactions to high-temperature, high-pressure reactors was highly promising, each product was separately optimized and therefore lacked the generality and synthetic tractability for fast and reliable compound library synthesis in drug discovery.…”

Synthesis and Antifungal Activity of the Derivatives of Novel Pyrazole Carboxamide and Isoxazolol Pyrazole Carboxylate

“…The synthesis of the derivatives of pyrazole carboxamide and isoxazolol pyrazole carboxylate is outlined in Scheme 1. Acetoacetic ester ( 1a – b ) and triethyl orthoformate were dissolved in acetic anhydride, refluxed and then converted into 2-ethoxymethylene acetoacetic ester derivatives ( 2a – b ) [19]. Ethyl 1 H -pyrazole-4-carboxylate ( 3a – b ) was prepared by reacting Compounds 2a – b with hydrazine hydrate [20].…”