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Pyrrolopyrimidine nucleosides. IV. The synthesis of certain 4,5‐disubstituted‐7‐(β‐d‐ribofuranosyl)pyrrolo[2,3‐ d ]pyrimidines related to the pyrrolo[2,3‐ d ]pyrimidine nucleoside antibiotics
Author(s) -
Hinshaw Barbara C.,
Gerster John F.,
Robins Roland K.,
Townsend Leroy B.
Publication year - 1969
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.5570060212
Subject(s) - chemistry , pyrimidine , nucleoside , nucleophile , stereochemistry , purine , pyrimidine analogue , yield (engineering) , ribonucleoside , substituent , organic chemistry , catalysis , biochemistry , rna , materials science , metallurgy , gene , enzyme
The treatment of 4‐chloro‐7‐(2′,3′,5′‐tri‐ O ‐acetyl‐β‐D‐ribofuranosyl)pyrrolo[2,3‐ d ]pyrimidine ( 4 ) with N ‐bromoacetamide in methylene chloride has furnished the 5‐bromo derivative of 4 which on subsequent deacetylation provided a good yield of 5‐bromo‐4‐chloro‐7‐(β‐D‐ribo‐furanosyl)pyrrolo[2,3‐ d ] pyrimidine ( 6 ). Assignment of the halogen substituent to position 5 was made on the basis of pmr studies. Treatment of 6 with methanolic ammonia afforded 4‐amino‐5‐bromo‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐ d ]pyrimidine ( 8 , 5‐bromotubercidin) and a subsequent study has revealed that the 4‐chloro group of 6 was replaced preferentially in a series of nucleophilic displacement reactions. The analogous synthesis of 4,5‐dichloro‐7‐(β‐D‐ribo‐furanosyl)pyrrolo[2,3‐ d ]pyrimidine ( 13b ) and 4‐chloro‐5‐iodo‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐ d ]pyrimidine ( 13a ) from 4 furnished 5‐chlorotubercidin ( 15 ) and 5‐iodotubercidin ( 14 ), respectively, on treatment of 13b and 13a with methanolic ammonia. The possible biochemical significance of these tubercidin derivatives is discussed.