An efficient approach to 1,4‐dihydropyridines containing novel substituted pyrazole is achieved via three‐component reaction of pyrazolyl aldehyde, β‐ketoester, and ammonium acetate in one‐pot under sulfamic acid catalysis.
Pumice-based sulfonic acid: a sustainable and recyclable acidic catalyst for one-pot synthesis of pyrazole anchored 1,4-dihydropyridine derivatives at room temperature
for the synthesis of pyrazole anchored 1,4-dihydropyridine analogs using pumice-based sulfonic acid (pumice@SO3H) as a recyclablesolidacidcatalyst under simple stirring at room temperature. The present protocol proceeded smoothly with 1,3-diaryl pyrazole-4-carbaldehydes, ethyl acetoacetate, and NH4OAc in ethanol as a solvent with excellent yield. The pumice-based sulfonic acidcatalyst is easily