Microwave-Assisted Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones Using Acid-Functionalized Mesoporous Polymer

Synthesis and application of acid-functionalized mesoporous polymer catalyst for the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones via Biginelli condensation reaction under microwave irradiation is investigated. Several analytical techniques such as FT-IR, BET, TEM, SEM and EDX were employed to characterize the synthesized polymeric catalyst. High acidity (1.15 mmol g-1 ), high surface area (90.44 m2 g -1 ) and mesoporous nature of the catalyst effectively promoted the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones. Microwave irradiation shows higher yield (89-98 %) as compared to conventional heating (15-25 % yield) under our optimized reaction conditions such as 1:1:1.2 molar ratio of aldehyde/ethylacetoacetate/urea, catalyst loading of 6 wt.% (with respect to aldehyde), the temperature of 80 °C and microwave power of 50 W. The synthesized Biginelli products were fully characterized by 1H and 13C NMR. The reusability of the catalyst was investigated up to 5 successive cycles and it showed great stability towards the synthesis of 3,4-Dihydropyrimidin-2(1H)-ones without any significant depreciation in yields

Sulphonated biomass-based catalyst for solketal synthesis by acetalization of glycerol – A byproduct of biodiesel production

Research on biomass-based catalyst is beneficial for the sustainability of biodiesel industry owing to its wide availability of feedstock, non-toxicity and biodegradability. Cellulose based heterogeneous solid carbon catalyst was prepared from cellulose by treating cellulose with concentrated sulphuric acid in innocuous hydrothermal conditions. It shows promising potential as a suitable catalyst for the synthesis of solketal (a biofuel additive) by acetalization of glycerol, the waste product of biodiesel production. 97.1 ± 0.4% of solketal was produced under the optimum conditions of 1:5 M ratio of glycerol and acetone, catalyst loading of 7 wt% at 70 °C in 10 min. 90% of catalytic activity was retained even after five catalytic cycles making the catalyst highly efficient. With further investments; this method may be used for the preparation of biofuel additive in an industrial level