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Saturated heterocycles, 248 . Synthesis of 2,4‐dioxo and 4‐oxo‐2‐thioxo derivatives of octahydrocyclopenta[ d ]pyrimidines
Author(s) -
Fülöp Ferenc,
Szakonyi Zsolt,
Bernáth Gábor,
Sohár Pál
Publication year - 1997
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570340419
Subject(s) - chemistry , cyclopentane , ring (chemistry) , potassium thiocyanate , thiocyanate , stereochemistry , cis–trans isomerism , d 1 , hydrolysis , cyanate , medicinal chemistry , closure (psychology) , organic chemistry , biochemistry , receptor , economics , market economy
Unsubstituted and 1‐benzyl‐substituted cis ‐cyclopenta[ d ]pyrirnidine‐2,4‐diones and cis ‐2‐thioxo‐cyclopenta[ d ]pyrimidin‐4‐ones 9a,b and 10a,b were prepared from the corresponding cis ‐2‐amino‐1‐cyclopentanecarboxylates 3 and 5 with potassium cyanate and thiocyanate. It was found that the cis derivatives 7a‐h readily underwent ring closure, resulting in 3‐substituted cis ‐2,4‐cyclopenta[ d ]pyrimidinediones and cis ‐2‐thioxocyclopenta[ d ]pyrimidin‐4‐ones 11a‐d and 12a‐d , whereas the trans counterparts 8a‐d failed to cyclize, but gave hydrolysed amino acid derivatives 13a,b and 14 . This difference in the reactivities of the cis and trans isomers is a further example of the difficulty of preparing cyclopentane trans ‐fused six‐membered 1,3‐heterocycles by ring closure.