The Identification of a Novel Highly Condensed Pentacyclic Heteroaromatic Ring System 1,3,5,5b,6,8,10,10b-Octaazacyclopenta[h,i]Aceanthrylene and its Application in the Synthesis of 5,7-Substituted Pyrazolo[4,3-d]Pyrimidines

• Published in: Journal of heterocyclic chemistry Vol. 52; no. 3; pp. 669 - 673
• Main Authors: Havlíček, Libor, Moravcová, Daniela, Kryštof, Vladimír, Strnad, Miroslav
• Format: Journal Article
• Language: English
• Published: HOBOKEN Blackwell Publishing Ltd 01.05.2015; Wiley; Wiley Subscription Services, Inc
• Subjects: 11-dichloro-1; 2-d; 2-k; 3-d]pyrimidine; 5,11‐dichloro‐1,7‐diisopropyldipyrazolo[4,3,2‐d,e; 4,3,2‐k,l]{pyrimido[4,5‐g]pteridine}; 5-g]pteridine; 7-diisopropyldipyrazolo; Chemistry; Chemistry, Organic; Cyclin-dependent kinases; fluorescence; kinase inhibitor; Kinases; l]{pyrimido; Physical Sciences; Protease inhibitors; pyrazolo; pyrazolo[4,3‐d]pyrimidine; roscovitine; Science & Technology; PURINES; e; 2-d; CANCER; OLOMOUCINE; roscovitine; 2-k; kinase inhibitor; l]{pyrimido; 3; 4; fluorescence; 5; 7-diisopropyldipyrazolo; 11-dichloro-1; 3-d]pyrimidine; pyrazolo; DEPENDENT KINASE INHIBITORS; 5-g]pteridine
• ISSN: 0022-152X; 1943-5193
• DOI: 10.1002/jhet.2147

Pyrazolo[4,3‐d]pyrimidines are of interest as potential kinase inhibitors. This article describes the formation of a novel highly conjugated, condensed, centrosymmetric heteroaromatic compound, 4,9‐dichloro‐2,7‐diisopropyl‐1,3,5,5b,6,8,10,10b‐octaazacyclopenta[h,i]aceanthrylene (3), during the chlorination of 5,7‐dihydroxypyrazolo[4,3‐d]pyrimidine (1) with phenylphosphonic dichloride. The nucleophilic attack of benzylamine on 3 afforded N‐benzyl‐5‐chloro‐3‐isopropyl‐1H‐pyrazolo[4,3‐d]pyrimidin‐7‐amine (6), which was further substituted to yield a pyrazolo[4,3‐d]pyrimidine analogue of roscovitine, a well‐known cyclin‐dependent kinase inhibitor.