19143-59-0Relevant articles and documents
Purines. XXX. Ring Fission of 3,7-Dialkyladenines by Alkaline Hydrolysis
Fujii, Tozo,Saito, Tohru,Inoue, Isao,Kumazawa, Yukinari,Tamura, Katsumi
, p. 107 - 117 (2007/10/02)
On treatment with boiling 1 N aqueous NaOH for 2 h, 3,7-dialkyladenine salts (7: R1, R2= Me, Et, or PhCH2; X= Br, I, or ClO4) gave 1-alkyl-4-(N-alkylamino)-1H-imidazole-5-carboxamides (8), 1-alkyl-4-amino-1H-imidazole-5-carboxamides (11), and N6,7-dialkyladenines (14) in 33-59 percent, 2-10 percent, and 2-5 percent yields, respectively.Under slightly milder reaction conditions, 3,7-dimethyladenine hydriodide (7a: X= I) afforded 1-methyl-4-(N-methylamino)-1H-imidazole-5-carboxamide (8a) together with 3,7-dimethylhypoxanthine (2a) as a by-product; 7-benzyl-3-methyladenine hydrobromide (7c: X= Br) furnished a small amount of 1-benzyl-4-(N-methylamino)-1H-imidazole-5-carboxamidine (5c) besides 1-benzyl-4-(N-methylamino)-1H-imidazole-5-carboxamide (8c), 1-benzyl-4-amino-1H-imidazole-5-carboxamide (11c), and 7-benzyl-N6-methyladenine (14c).These results are best interpreted in terms of pathways involving hydrolytic deamination, ring fission in the pyrimidine and imidazole moieties, cyclization, and Dimroth rearrangement.The instability of 7a (X= I) in aqueous alkali was compared with that of the four possible Nx,9-dimethyl isomers, and the relative ease with which the adenine ring underwent hydrolytic ring fission was found to decrease in the order 3,9- (17) >7,9- (18) >1,9- (19) >3,7- (7a) >>N6,9-dimethyl isomer (20).Keywords - 3,7-dialkyladenine alkaline hydrolysis; ring fission; deamination; rearrangement; 1-alkyl-4-(N-alkylamino)-1H-imidazole-5-carboxamide; 1-alkyl-4-amino-1H-imidazole-5-carboxamide; N6,7-dialkyladenine
