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Synthesis of 1,5‐dihydro‐5‐(4‐methoxyphenyl)‐4 H ‐pyrazolo[3,4‐ d ]pyrimidin‐4‐ones and their ribosides and mannich bases
Author(s) -
Finlander Peter,
Pedersen Erik B.
Publication year - 1985
Publication title -
archiv der pharmazie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 61
eISSN - 1521-4184
pISSN - 0365-6233
DOI - 10.1002/ardp.19853180512
Subject(s) - chemistry , piperidine , triethyl orthoformate , formaldehyde , mannich reaction , reagent , medicinal chemistry , organic chemistry , catalysis
1,5‐Dihydro‐4 H ‐pyrazolo[3,4‐ d ]pyrimidin‐4‐ones 5 and 6 were prepared by reaction of the corresponding ethyl 5‐aminopyrazole‐4‐carboxylate with triethyl orthoformate and amines. Ethyl N ‐(4‐methoxyphenyl)formimidate and N,N ′‐bis(4‐methoxyphenyl)formamidine could also be used as the ring closing reagent. The Mannich bases 13 and 14 were produced in a reaction of 9 with formaldehyde and piperidine. The ribosides 15 were obtained by melting a mixture of 9 and 1,2,3,5‐tetra‐ O ‐acetyl‐β‐ D ‐ribofuranose in the presence of p ‐toluenesulphonic acid.