Synthesis and high resolution proton NMR studies on isomeric N-1-/N-2,5,7-trisubstituted-4,6-dioxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines

Authors
Avasthi, K Chandra, T Rawat, DS Bhakuni, DS
Citation
K. Avasthi et al., Synthesis and high resolution proton NMR studies on isomeric N-1-/N-2,5,7-trisubstituted-4,6-dioxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines, I J CHEM B, 37(12), 1998, pp. 1228-1233
Citations number
15
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
INDIAN JOURNAL OF CHEMISTRY SECTION B-ORGANIC CHEMISTRY INCLUDING MEDICINAL CHEMISTRY
ISSN journal
03764699 → ACNP
Volume
37
Issue
12
Year of publication
1998
Pages
1228 - 1233
Database
ISI
SICI code
0376-4699(199812)37:12<1228:SAHRPN>2.0.ZU;2-M
Abstract
Unambiguous synthesis of all six possible 1/2,5,7-trisubstituted (monobenzy l,dimethyl)-4,6-dioxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines has been described. High resolution (400 MHz) proton NMR data of these compounds (1 0, 13, 19, 25a, 25b and 25c) have been discussed and some unusual features observed for phenyl protons have been rationalized due to hindered rotation when two substituents are simultaneously present at 1- and 7-positions.