The mol-ecular structure of the title compound, C(8)H(12)N(2)O, indicates that 2-isopropyl-6-methyl-pyrimidin-4-ol (the enol-form) undergoes an enol-to-keto tautomerism during the crystallization process. The pyrimidin-4(3H)-one group is essentially planar, with a maximum deviation of 0.081 (1) Å for the O atom. In the crystal structure, symmetry-related mol-ecules are linked into centrosymmeti...

The first systematic steady-state and time-resolved emission study of firefly oxyluciferin (emitter in firefly bioluminescence) and its analogues in aqueous buffers provided the individual emission spectra of all chemical forms of the emitter and the excited-state equilibrium constants in strongly polar environment with strong hydrogen bonding potential. The results confirmed the earlier hypoth...

The mol-ecule of the title compound, C(21)H(16)N(2)O, exists in the keto form and the C=O and N-H bonds are mutually cis in the crystal structure, although an enol form would be possible through tautomerism. The dihedral angle between the quinoline and the naphthalene systems is 22.04 (2)°. A bifurcated intramolecular N-H⋯(O,N) hydrogen bond is present.

Biologically and pharmaceutically active core structures containing a new class of 4-hydroxy-α-carbolines, dihydropyrido[2,3-b]indoles, pyrimido[4,5-b] and [5,4-b]indoles have been synthesized in good yields via Pd-catalyzed amidation and cyclizations. The keto-enol tautomerism in 4-hydroxy-α-carbolines has been investigated by DFT calculations and spectroscopic techniques. The fluorescence stu...

androstane skeleton with a keto-enol tautomerism at the cyclopentane ring. Wecarried out further isolation for PFTase inhibitors from the cultured broth of strain FO-3929 and found andrastin D (4, Fig. 1). In this paper, fermentation, isolation, structure elucidation, and biological properties of 4 are described. A stock culture of strain FO-3929 was inoculated into six 500-ml Erlenmeyer flasks...

In this laboratory exercise we will measure the Equilibrium Constant Kc for the keto-enol tautomerism of two -diketones and two -diketoesters. This will be accomplished by measuring the signal strength of key protons in the Nuclear Magnetic Resonance (NMR) spectrum of the equilibrium system. The influence of the solvent on the equilibrium position will be examined by considering the measured ...

The Acamprosate is a significant drug for alcohol abuse therapy, which may be an effective treatment for tinnitus, too. The Acamprosate has two possible tautomers, Keto and Enol tautomers. Each of the tautomers involves two important conformers. In this work, employing density functional theory (DFT) and handling the solvent effects with the PCM model, the structural parameters, energetic behav...