The gas phase acidities of a series of uracil derivatives (1-methyluracil, 3-methyluracil, 6-methyluracil, 5,6-dimethyluracil, and 1,3-dimethyluracil) have been bracketed to provide an understanding of the intrinsic reactivity of uracil. The experiments indicate that in the gas phase, uracil has four sites more acidic than water. Among the uracil analogs, the N1-H sites have deltaH(acid) values...

A simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([BMIm]Br) under solvent-free conditions is reported. The presented method is benefited from operational simplicity...

In contrast to the previously reported short time required (1 h) for photolysis of 6-chloro-1,3-dimethyluracil (6-CIDMU) and mesitylene, in the presence of TFA, resulting in two major products: 1,3,6,8,10-pentamethylcyclooctapyrimidine derivative (1d), and diazapentacyclo[6.4.0.0(1,3).0(2,5).0(4,8)]dodecane (2c), prolonged irradiation (18h) of this same mixture yields novel pentalenopyrimidine ...

Proton transfer is ubiquitous in chemistry and biology, occurring, for example, in proteins, enzyme reactions and across proton channels and pumps. However, it has always been described in the context of hydrogen-bonding networks ('proton wires') acting as proton conduits. Here, we report efficient intramolecular ionization-induced proton transfer across a 1,3-dimethyluracil dimer, a model π-st...

A green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of β-naphthol, aldehyde, and 6-amino-1,3-dimethyluracil using L-proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100 °C is described. In this study, several types of aromatic aldehyde, containing electron-withdrawing groups as well ...

A green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of β-naphthol, aldehyde, and 6-amino-1,3-dimethyluracil using L-proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100 °C is described. In this study, several types of aromatic aldehyde, containing electron-withdrawing groups as well ...