Synthesis of Adenines with a Phosphorus-Containing Group in the 9-Position

Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

“…Similarly, a reaction of compounds 8 having two N- (4,4-diethoxybutyl)urea moieties connected via polymethylene or 1,4-phenylene spacer give diastereomeric bis(2-aryl)pyrrolidines 9 (Scheme 3).. [25][26][27] The synthetic outcome of a reaction of bis(ureas) 8 with resorcinol derivatives depends on a structure of starting compound and reaction conditions (Scheme 5). [38,39] The reaction of urea 8 possessing hexamethylene spacer with two equivalents of resorcinol, 2-methylresorcinol, or pyrogallol in chloroform, benzene, or acetone in the presence of trifluoroacetic acid failed to produce the desired compounds. In all cases a complex mixture of polymeric products was formed.…”

“…Bis(urea) 8 having 1,4phenylene spacer reacted with resorcinol, 2-methylresorcinol, and pyrogallol to give a new class of macroheterocyclic compounds 11. [39] Notably, although the reactions were carried out without resorting to techniques specific to a synthesis of macrocyclic compounds (i. e., strong dilution of the reaction mixture), macrocycles 11 were isolated with more than 60% yield. This may be due to low solubility of the products 11 and starting bis(urea) 8 in chloroform, which ensured very low concentrations of reactants in solution.…”

“…As a result, a series of previously unknown 2-(pyrazole-4-yl)pyrrolidines 12 were obtained with ∼ 70% yield (Scheme 6). [40]…”