RESUMO
Ultrasonic irradiation was used in the synthesis of a series of novel 1,2,4-triazolo[1,5-a]pyrimidines. The products were synthetized from the cyclocondensation reaction of 1,1,1-trifluoro-4-metoxy-3-alken-2-one [CF3C(O)CHC(R)OMe, where R=Ph, 4-F-C6H4, 4-Br-C6H4, 4-I-C6H4, 4-CH3-C6H4, 4-CH3O-C6H4, Thien-2-yl, Biphen-4-yl] or ß-enaminones [RC(O)CHCHNMe2, where R=Ph, 4-F-C6H4, 4-Br-C6H4, 4-I-C6H4, 4-CH3-C6H4, 4-CH3O-C6H4, 4-NO2-C6H4, Thien-2-yl, Biphen-4-yl, Naphth-2-yl, Pyrrol-2-yl, CCl3] with 5-amino-1,2,4-triazole in acetic acid at 99°C with 5-17 min of ultrasound irradiation. This methodology has shown several advantages, such as shorter reaction times, mild conditions, high regioselectivity, and excellent yields, when compared with conventional thermal heating (oil bath).
Assuntos
Pirimidinas/síntese química , Triazóis/síntese química , Ultrassom , Técnicas de Química Sintética , Pirimidinas/química , Triazóis/químicaRESUMO
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%).
Assuntos
Pirazóis/síntese química , Pirimidinas/síntese química , Sonicação , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Pirazóis/química , Pirimidinas/químicaRESUMO
In the title compound, C(15)H(12)F(3)N(3), the pyrazolo[1,5-a]pyrimidine system ring is essentially planar with a maximum deviation from the mean plane of 0.014â (1)â Å. The 4-tolyl group makes a dihedral angle of 14.1â (1)° with the pyrazolo[1,5-a]pyrimidine ring system. The crystal packing is stabilized mainly by van der Waals forces.