In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.

Mild and applicable synthesis of mono-, bis-, and spiro- perimidines is demonstrated in high yields via the condensation of 1,8-diaminonaphthalene and aldehydes or ketones in the presence of sulfamic acid as a green and highly efficient catalyst. This environmentally benign and clean synthetic pathway offers several advantages, such as high yields, short reaction times and easy work-up procedure.

An efficient one-pot condensation for the synthesis of 1,8-dioxo-octahydroxanthene is  achieved through a condensation of aryl aldehydes and 5,5-dimethyl-1,3-cyclohexandione in the presence of  NBS. This method enjoys several advantages such as low cost, simple work up procedure and safe reaction condition. In addition, water was chosen as a green solvent.

In this paper, a new two-sampling scheme is proposed to construct appropriate confidence intervals for the lower population quantiles. The confidence intervals are determined in the parametric and nonparametric set up and the optimality problem is discussed in each case. Finally, the proposed procedure is illustrated via a real data set. 

Benzylaminoalkenones and benzylaminoalkenoates 3 were synthesized from reaction of benzylamine with corresponding 1,3-diketones and 1,3-ketoesters in the presence of catalytic amount of chloroacetic acid under microwave radiation. This method offers several advantages including high yield of products, recyclable of the catalyst and easy experimental work-up procedure.

Trichloroacetic Acid (TCA) was used as an efficient catalyst for the synthesis of highly functionalized piperidines via a one-pot five-component reaction of aromatic amines, aromatic aldehydes and β-keto esters in MeOH at room temperature. The remarkable advantages offered by this method are good yields, simple procedure, short reaction times, no need to column chromatography and an easy wo...

An efficient synthesis of 2H-thiopyran derivatives via three-component reaction of alkyl propiolate, benzoyl isothiocyanate or its derivatives and alkyl bromides in the presence of triphenylphosphine in water at 80o C without using any catalyst in water is described. The method offers several advantages including high yields of products and an easy work-up procedure.

Mild and applicable synthesis of mono-, bis-, and spiro- perimidines is demonstrated in high yields via the condensation of 1,8-diaminonaphthalene and aldehydes or ketones in the presence of sulfamic acid as a green and highly efficient catalyst. This environmentally benign and clean synthetic pathway offers several advantages, such as high yields, short reaction times and easy work-up procedure.