Eco-Friendly Methodology to Prepare N-Heterocycles Related to Dihydropyridines: Microwave-Assisted Synthesis of Alkyl 4-Arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate and 4-Arylsubstituted-4,7-dihydrofuro[3,4-b]pyridine-2,5(1H,3H)-dione
Here we describe the efficient synthesis of alkyl 4-arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylates and 4-arylsubstituted-4,7-dihydro-furo[3,4-b]pyridine-2,5(1H,3H)-diones via microwave-accelerated reaction of alkyl 4-arylsubstituted-2-methyl-6-oxo-1,4,5,6-tetrahydro-3-pyridinecarboxylates with the appropriate reagents. This eco-friendly approach to these valuable dihydropyridine derivatives does not involve the harsh or highly contaminating conditions common in classical heating and offers a reduction or even elimination of solvent use and recovery, simplification of the work-up procedures, facility of scale up, and low energy consumption, in addition to moderate to higher yields.
facile, efficient and environment-friendly protocol for the synthesis of 6-chloro-5-formyl-1,4-dihydropyridine derivatives has been developed by the convenient ultrasound-mediated reaction of 2(1H)pyridone derivatives with the Vilsmeier-Haack reagent. This method provides several advantages over current reaction methodologies including a simpler work-up procedure, shorter reaction times and higher yields
Electron-transfer induced oxidation of 2-oxo-1,2,3,4-tetrahydropyridines using TiO2 anatase-nanoparticles: steric and electronic substitution effects
作者:Hamid Reza Memarian、Mahdieh Kalantari
DOI:10.1007/s13738-018-1407-y
日期:2018.9
The steric and electroniceffects of 4-substitution in various 4-aryl substituted 5-carboethoxy-2-oxo-1,2,3,4-tetrahydropyridines were investigated by exposing them to the UV-light in the presence or absence of the TiO2 anatase-nanoparticles. The results clearly indicate the effective presence of the photo-catalyst and also the electron-donating effect of 4-aryl substitution on drastic decreasing of
The title compounds 6 have been prepared in a one-step procedure from the corresponding 4-aryl substituted 5-alkoxycarbonyl-6-methyl-3,4-dihydropyridones 4 in good yields. Quantum chemical calculations reveal a non-planar molecule with a distorted dihydropyridone ring and two favoured conformations. The 13C nmr data and theoretical calculations support a strong push-pull effect on the olefinic moiety
High-throughput preparation of alkyl 4-aryl substituted-2-methyl-6-thioxo-1,4,5,6-tetrahydropyridine-3-carboxylates under microwave irradiation
作者:Hortensia Rodríguez、Julieta Coro、Anabel Lam、Esperanza Salfrán、Javier Rodríguez-Salarichs、Margarita Suárez、Fernando Albericio、Nazario Martin
DOI:10.3998/ark.5550190.0012.909
日期:——
An efficient high-throughput synthesis of 4-aryl substituted 1,4,5,6-tetrahydro-2-methyl-6thioxopyridine-3-carboxylates 5a-p was developed by using Lawesson’s reagent, a very effective thionating reagent for carbonyl compounds, under conventional conditions and microwaveirradiation. In order to gain a better understanding of the structure of the heterocycles obtained, theoretical calculations at the