1,3-dipolar cycloaddition reactions in the series of N-alkynyl-substituted uracils

Abstract

Reactions of 1-(ω-bromoalkyl)-3,6-dimethyluracils and 1,3-bis(ω-bromoalkyl)-6-methyluracils with sodium azide gave the corresponding mono-and bis-azides. 1,3-Dipolar cycloaddition of the latter with prop-2-yn-1-ol, hex-1-yne, and dec-1-yne in the presence of copper(I) ions afforded acyclic and macrocyclic uracil derivatives containing 1,4-disubstituted 1,2,3-triazole fragments, which were subjected to quaternization with propyl iodide and methyl p-toluenesulfonate at the 1,2,3-triazole nitrogen atom.

Novel Acetylcholinesterase Inhibitors Based on Uracil Moiety for Possible Treatment of Alzheimer Disease

“…Attempt of direct substitution of Br in dibromide 5b by NH 2 in ammonia solution was unsuccessful. Then dibromide 5b was converted to azide 11 [ 30 ] and the Staudinger reaction [ 31 ] of the azide with triphenylphosphine gave bisamine 12 . The aimed secondary bisamine 3 was prepared reacting 12 with 2-nitrilebenzaldehyde and reducing intermediate aldoimine 13 with NaBH 4 ( Scheme 3 ).…”

“…Synthesis of initial compounds 1,3-bis(4-bromobutyl)-6-methyluracil ( 7a ), 1,3-bis(5-bromopentyl)-6-methyluracil ( 7b ), 1,3-bis(6-bromohexyl)-6-methyluracil ( 7c ) [ 35 ], 1,3-bis(4-ethylaminobutyl)-6-methyluracil ( 8a ), 1,3-bis(5-ethylaminopentyl)-6-methyluracil ( 8b ), 1,3-bis(6-ethylaminohexyl)-6-methyluracil ( 8c ) [ 28 , 29 ], 1,3-bis(5-azidopentyl)-6-methyluracil ( 11 ) [ 30 ], and 1,3-bis(5-bromopentyl)quinazoline-2,4-dione ( 9b ) was carried out as previously reported [ 36 ].…”

Supramolecular Systems Based on Novel Amphiphiles and a Polymer: Aggregation and Selective Solubilization

“…Compound Tr (oil) in turn was synthesized as described in Semenov et al () by substituting the bromine atoms for azide groups in 1,3‐bis(5‐bromopentyl)‐6‐methyl‐2,4‐dioxopyrimidine and introducing the resulting compound 1,3‐bis(5‐azidopentyl)‐6‐methyl‐2,4‐dioxopyrimidine into the 1,3‐cycloaddition reaction with propargyl alcohol (Scheme ).…”

“…3, 151.1, 142.6, 129.2, 100.5, 58.1, 53.0, 52.9, 51.5, 50.4, 43.9, 39.4, 30.8, 28.5, 27.9, 25.3, 23.2, 22.3, 21.6, 18.8, 13.1, and 12.8. Fourier-transform infrared spectrum (film, KBr, cm −1 ) ν: 3912, 3250, 2956, 2927, 2856, 2096, 1698, 1658, 1620, 1531, 1466, 1432, 1403, 1361, 1246, 1178, 1045, 817, 770, 627, 550, and 416 H 8.26;N 12.41;and Br 17.69. Compound Tr (oil) in turn was synthesized as described in Semenov et al (2012) by substituting the bromine atoms for azide groups in 1,3-bis(5-bromopentyl)-6-methyl-2,4-dioxopyrimidine and introducing the resulting compound 1,3-bis(5-azidopentyl)-6-methyl-2,4-dioxopyrimidine into the 1,3-cycloaddition reaction with propargyl alcohol (Scheme 2).…”

Aerobic oxidations in flow: opportunities for the fine chemicals and pharmaceuticals industries

“…The inability to efficiently remove the reaction heat can lead to explosive chemical reactions, and their theoretical description is addressed in the seminal works of Semenov 33 and Frank-Kamenetskii. 34 The underlying basis of both theories is that the ignition of a reactive mixture is attributed to the fact that the production rate of heat (i.e.…”