Potassium phthalimide: An efficient and green organocatalyst for the synthesis of 4-aryl-7-(arylmethylene)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-ones/thiones under solvent-free conditions

Grinding Synthesis of Pyrazolyl-Bis Coumarinyl Methanes Using Potassium 2-Oxoimidazolidine-1,3-diide

AIM AND OBJECTIVE

Potassium 2-oxoimidazolidine-1,3-diide (POImD) as a novel and reusable catalyst was used for the synthesis of pyrazolyl-bis coumarinyl methanes by a nucleophilic addition reaction of synthetized pyrazolecarbaldehyde and two equivalents of 4-hydroxycoumarin under grinding. The catalyst can be reused and recovered several times without loss of activity. This method provides several advantages such as eco-friendliness, simple work-up and shorter reaction time as well as excellent yields. All of the synthesized compounds were characterized by IR, 1H and 13C NMR spectroscopy and elemental analyses.

MATERIAL AND METHOD

Synthetized pyrazole carbaldehyde 1a (1 mmol), 4-hydroxycoumarin 2 (2 mmol), 1 mmol of POImD and 10mL of H2O were ground in a mortar by a pestle for 30-90 minutes. After the completion of the reaction, as monitored by TLC on silica gel using ethyl acetate/n-hexane (1:2), the mixture was allowed to cool to room temperature. After completion of the reaction, we extracted the product with CH2Cl2/H2O. This was followed by separation of phases, evaporation of the organic phase and recrystallization of the residue with 50 mL of ethanol/H2O (1:1). The pure product was then obtained in 87 to 96% yield. The aqueous phase was concentrated under reduced pressure to recover the catalyst for subsequent use.

RESULTS

To continue our ongoing studies to synthesize heterocyclic and pharmaceutical compounds by mild, facile and efficient protocols, herein we wish to report our experimental results on the synthesis of pyrazolylbis coumarinyl methanes, using various synthetized pyrazole carbaldehydes and 4-hydroxycoumarin in the presence of POImD in aqueous media at room temperature.

CONCLUSION

Finally, we developed an efficient, fast and convenient procedure for the three-component synthesis of pyrazolyl-bis coumarinyl methanes through the reaction of pyrazole carbaldehydes and 4- hydroxycoumarin, using POImD as a novel and reusable catalyst. The remarkable advantage offered by this method is that the catalyst is non-toxic, inexpensive, easy to handle and reusable. A short reaction time, simple work-up procedure, high yields of product with better purity and the green aspect by avoiding a hazardous solvent and a toxic catalyst are the other advantages. To the best of our knowledge, this is the first report on the synthesis of pyrazolyl-bis coumarinylmethane derivatives using potassium 2-oxoimidazolidine-1,3-diide (POImD).

Screening for strains with 11α-hydroxylase activity for 17α-hydroxy progesterone biotransformation

Various corticosteroids are prepared by using 11α,17α-diOH-progesterone (11α,17α-diOH-PROG) as an important intermediate and raw material. Hence, strains that can improve the yields of 11α,17α-diOH-PROG should be screened. Cunninghamella elegans CICC40250 was singled out from five common 11α hydroxylation strains. The reaction parameters of 11α,17α-diOH-PROG production were also investigated. C. elegans CICC40250 could efficiently catalyze the hydroxylation of 17α-hydroxy progesterone (17α-OH-PROG) at C-11α position. This strain could also effectively convert 11α,17α-diOH-PROG at high substrate concentrations (up to 30g/L). After the coenzyme precursor glucose was added, the rate of 11α,17α-diOH-PROG formation reached 84.2%, which was 11.4% higher than that of the control group. Our study established a simple and feasible mechanism to increase 11α,17α-diOH-PROG production levels. This mechanism involves C. elegans CICC40250 that can be efficiently applied to induce the biotransformation of 17α-OH-PROG with a hydroxylation biocatalytic ability.

Experimental and Theoretical Thermochemistry of the Isomers 3- and 4-Nitrophthalimide

This work presents a thermochemical study of two derivatives of phthalimide: the isomers 3-nitrophthalimide and 4-nitrophthalimide. The enthalpies of formation for these compounds in the solid phase were obtained by combustion calorimetry. Using ths thermogravimetry technique, the enthalpies of vaporization were obtained. The enthalpies of sublimation were calculated from enthalpies of fusion and vaporization. From experimental data and by ab initio methods, the enthalpies of formation in the gas phase were calculated. With these results, it was possible to determine their relative stability, and it was found that 4-nitrophthalimide is more stable than its isomer 3-nitrophthalimide. This tendency is similar to that of 3-nitrophthalic anhydride and 4-nitrophthalic anhydride, as reported in a previous work by our research group. The enthalpy of isomerization was also obtained, and a good correlation with that of phthalic anhydride derivatives was found. Finally, with the values obtained, the enthalpic difference resulting when the imide group is substituted by an anhydride group was determined.

Synthesis of β-phthalimido-alcohols via regioselective ring opening of epoxide by using reusable basic magnetic nano particles and their biological investigation

In this work, regioselective ring opening of epoxides including aromatic and aliphatic epoxides to give β-phthalimido-alcohols has been reported.