Abstract
An efficient and simple one-pot synthesis of some new symmetrical, unsymmetrical and Nsubstituted Hantzsch 1,4-dihydropyridines using molecular iodine as catalyst from an aldehyde, a 1,3-dicarbonyl compound and ammonium acetate / aromatic amine in ethanol is described. This new method has the advantage of good to excellent yields (80-95%) and short reaction times (2.5-5 h) at ambient temperature.
Highlights
Hantzsch 1,4-dihydropyridines (1,4-DHPs) and their derivatives have gained great importance in the field of organic and medicinal chemistry since they display a fascinating array of pharmacological properties.[1,5]
The dihydropyridine skeleton is common in many drugs such as nifedipine, nicardipine, amlodipine and others, which are effective as cardiovascular agents and which are used for the treatment of hypertension.6,7 1,4-DHPs have been explored for their calcium channel modulation[8,9] and the heterocyclic rings are found in a variety of bioactive compounds such as vasodilator, bronchodilator, antiatherosclerotic, antitumor, antidiabetic, geroprotective and heptaprotective agents.[10,11,12,13]
Due to some disadvantages of this method, there are several efficient methods developed for the synthesis of 1,4-DHPs, which comprise the use of microwave,[17,18] ionic liquid,[20,21] high temperature in refluxing solvents,[22,23,24,25] TMSCl-NaI26 and metal triflates.[27]
Summary
Hantzsch 1,4-dihydropyridines (1,4-DHPs) and their derivatives have gained great importance in the field of organic and medicinal chemistry since they display a fascinating array of pharmacological properties.[1,5] The dihydropyridine skeleton is common in many drugs such as nifedipine, nicardipine, amlodipine and others, which are effective as cardiovascular agents and which are used for the treatment of hypertension.6,7 1,4-DHPs have been explored for their calcium channel modulation[8,9] and the heterocyclic rings are found in a variety of bioactive compounds such as vasodilator, bronchodilator, antiatherosclerotic, antitumor, antidiabetic, geroprotective and heptaprotective agents.[10,11,12,13] They even possess neuroprotective platet antiaggregation activity.[14]. Reaction of various aldehydes 1 reacted smoothly with 1,3-dicarbonyl compounds 2, methyl acetoacetate 5 and ammonium acetate 3 under these reaction conditions to give the corresponding unsymmetrical 1,4-DHPs derivatives 6a-f in 88-94% yield under ambient conditions (Scheme 2).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
