A facile, regioselective synthesis of novel 3-(N-phenylcarboxamide)pyrazolo[1,5-a]pyrimidine analogs in the presence of KHSO4 in aqueous media assisted by ultrasound and their antibacterial activities.
An environmentally benign, simple, efficient, and convenient route is described for the synthesis of novel pyrazolo[1,5-a]pyrimidine derivatives under ultrasound irradiation. Condensation of aminopyrazole 5 with formylated active proton compounds (6, 8, E-G, 12, and 15) furnished pyrazolopyrimidine (7, 9, 10, 13, and 16) in high-to-excellent yields. In comparison with conventional methods, ultrasound irradiation offers several advantages, such as shorter reaction time, higher yields, milder conditions, and environmental friendliness. The reaction is clean with excellent yields and reduces the use of solvents. X-ray crystallographic study of compound 7c confirmed the regioselectivity of the reaction. The antibacterial profile of the newly synthesized compounds was evaluated by cup and saucer method.
Organic Research Laboratory, Department of Chemical Science, Assam Don Bosco University, Airport Road-Azara, Guwahati, 781017, India.
Shunan
S
Kaping
Department of Biotechnology, St. Anthonys College, Shillong, 793001, India.
Ivee
I
Boiss
Department of Biotechnology, St. Anthonys College, Shillong, 793001, India.
Laishram Indira
LI
Singha
Laboratoire de Chimie Thérapeutique, UMR CNRS No. 8638, Université Paris Descartes, Faculte des Sciences Pharmaceutiques et Biologiques, 75270, Paris Cedex 06, France.
Philippe
P
Helissey
Organic Research Laboratory, Department of Chemical Science, Assam Don Bosco University, Airport Road-Azara, Guwahati, 781017, India. jnvishwakarma@rediffmail.com.
Jai N
JN
Vishwakarma
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013237:Stereoisomerism; D013431:Sulfates / Q000737:chemistry*; D000069453:Ultrasonic Waves; D014867:Water / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D011743:Pyrimidines; D013431:Sulfates; D014867:Water; C031512:potassium sulfate; C030986:pyrimidine
5-Aminopyrazoles; Antibacterial; Condensation; Formylation; Pyrazolopyrimidines; Ultrasound irradiation; X-ray crystallography