title: An efficient Synthesis and Photophysical Properties of 1H-pyrazolo-[3,4-b]pyridine and pyrazolo[3,4-b][1,8]naphthyridines.
abstract: A novel synthon 6-amino-3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b] pyridine-5-carbaldehyde 4 was synthesized by multistep process. Then Friedlander condensation of this synthon with reactive methylenes was performed to achieve interesting tricyclic 6a-b, tetracyclic 6d and pentacyclic 6c N-heterocycles in excellent yield. The absorption and emission spectra of compounds 1-4 and 6 were measured and observed that the absorption and emission depends on the substituent at C-6 and C-7 position of pyridine ring in naphthyridines skeleton 6.
authors.affiliation: Organic Chemistry Research Centre, Department of Chemistry, K.T.H.M. College, Gangapur Road, Nashik, 422002, Maharashtra, India.|Savitribai Phule Pune University, Pune, India.
authors.forename: Raviraj
authors.initials: R
authors.lastname: Deore
authors.affiliation: Organic Chemistry Research Centre, Department of Chemistry, K.T.H.M. College, Gangapur Road, Nashik, 422002, Maharashtra, India.|Savitribai Phule Pune University, Pune, India.
authors.forename: Kunal
authors.initials: K
authors.lastname: Dingore
authors.affiliation: Organic Chemistry Research Centre, Department of Chemistry, K.T.H.M. College, Gangapur Road, Nashik, 422002, Maharashtra, India. mnjachak@hotmail.com.|Savitribai Phule Pune University, Pune, India. mnjachak@hotmail.com.
authors.forename: Madhukar
authors.initials: M
authors.lastname: Jachak
keywords: 3-(4-methoxyphenyl)-1-phenyl-6,7,8,9-tetrahydro-1H-benzo[b]pyrazolo[4,3-b][1,8]naphthyridines; 6-amino-3(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbaldehyde; Absorption and emission spectra; Fluorescence; Quantum yield; pyrazolo[3,4-b][1,8]naphthyridines