Clarissa P. Frizzo was born in Ivora ´, Rio Grande do Sul state, Brazil, in 1983. She received her undergraduate degree in Pharmacy from the Federal University of Santa Maria in 2005, and in 2007 she obtained her M.Sc. degree from the Federal University of Santa Maria, under the supervision of Professor Marcos A. P. Martins, working with the use of ionic liquids in the synthesis of heterocycles. She started her Ph.D. studies under the supervision of Professor Marcos A. P. Martins, and currently she is focusing on her Sandwich Ph.D. in the Universidade Nacional de Educacio ´n a Distancia in Spain, under the guidance of Professor Rosa M. Claramunt Vallespı ´, where she is studying the supramolecular structure of heterocycles. Dayse das Neves Moreira was born in Canguc ¸u, Rio Grande do Sul state, Brazil, in 1984. She received her undergraduate degree in Chemistry from the Federal University of Pelotas, RS, in 2006, and in 2008 she received her M.S. degree, from the Federal University of Santa Maria, RS, Brazil, working under the direction of Professor Marcos A. P. Martins, working with the use of ionic liquids in the synthesis of heterocycles. Currently, she is a Ph.D. student with Professor Marcos A. P. Martins in the Department of Chemistry of the Federal University of Santa Maria. Her major research interest is to develop new methodologies to synthesize heterocyclic compounds. Lilian Buriol was born in Santa Izabel do Oeste, Parana ´(PR) state, Brazil, in 1984. She received her undergraduate degree in Chemistry from the State University of Centro-Oeste (PR). In 2008, she completed her M.S. degree at the same university under the supervision of Professor Yohandra R. Torres, working with oil and ethanol extracts of propolis. After that, she started her Ph.D. studies in the Department of Chemistry of the Federal University of Santa Maria under the supervision of Professor Marcos A. P. Martins. Her research interest is to develop new methodologies to synthesize heterocyclic compounds along the lines of green chemistry.

Establishment of CH···π interactions between the aliphatic axis and the benzylic amide macrocycle of hydrogen-bonded [2]rotaxanes causes a measurable interference in the pirouetting submolecular motion of these interlocked molecules.

The dethreading of a series of succinamide-based [2]rotaxanes bearing benzylic amide macrocycles is reported herein. These transformations proceeded quantitatively either under flash vacuum pyrolysis, conventional heating, or microwave irradiation. Studying the size complementarity of the stoppers at the ends of the thread and the cavity of the macrocycle allowed us to set up the best substituents for implementing the extrusion of the thread from the interlocked precursors. A variety of (1)H NMR kinetic experiments were carried out in order to evaluate the rate constants of the dethreading process, the half-life times of the rotaxanes, and the influence of temperature and solvents on these processes. The use of dibutylamino groups as stoppers yielded the rotaxane precursor in a reasonable yield and allowed the quantitative deslipping of the rotaxane. The overall process, including the rotaxane formation and its further dethreading, has been exploited for preparing benzylic amide macrocycles enhancing, in most cases, the results of the classical (2 + 2) condensation and other reported stepwise syntheses. The kinetics of the dethreading process is fairly sensitive to the electronic effects of the substituents on the isophthalamide unit or to the electronic nature of the pyridine rings through a conformational equilibrium expanding or contracting the cavity of the interlocked precursor.

Pyrazolo[1,5-a]pyrimidines were synthesized via the ultrasonic sonochemical method using the cyclocondensation reaction of 4-alkoxy-1,1,1-trifluoro-3-alken-2-ones [CF3C(O)CH=C(R)(OMe) - where R=Me, Bu, i-Bu, Ph, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, naphth-2-yl and biphen-4-yl] - with 3-amino-5-methyl-1H-pyrazole in the presence of EtOH for 5 min. This methodology has several advantages, for example, it is a simple procedure, it has an easy work-up, mild conditions, short reaction times (5 min) and produces satisfactory yields (61-98%).