- Structures of 1,2,3,4-tetrahydro-6H-pyrimidoquinazolin-6-one and its hydrochloride
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C11H11N3O, m.p. 243 deg C, P2/n, Z = 4, a = 5.843(2), b = 14.241(3), c = 11.102(1) Angstroem, β = 93.30(2) deg, R = 0.046; C11H11N3O*HCl*H2O, Pca21, Z = 8, a = 18.640(2), b = 8.894(2), c = 14.404(2) Angstroem, R = 0.062.The molecules of the free base are in 1H-tautomeric form.N(1)-H...N(11) hydrogen bonds join molecules of the free base into dimers, which enable tautomeric rearrangement (not observed in this study) also in the solid state without any changes in molecular packing.The quinazoline system deviates slightly from planarity and benzene ? electrons are partially localized at C(7)-C(8) and C(9)-C(10) bonds as seen from their lengths of about 1.375 Angstroem, while other bonds in the benzene ring are at least 0.02 Angstroem longer.Key words: Pyrimidoquinazoline, hydrochloride, neuroleptic.
- Glowka, Marek L.,Olczak, Andrzej,Korzycka, Lucyna
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- Cyclic acyl guanidines bearing carbamate moieties allow potent and dirigible cholinesterase inhibition of either acetyl- or butyrylcholinesterase
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A series of cyclic acyl guanidine with carbamate moieties have been synthesized and evaluated in vitro for their AChE and BChE inhibitory activities. Structure-activity relationships identified compound 23 as a nanomolar and selective BChE inhibitor, while compound 32 exhibited nanomolar and selective AChE inhibition, selectivity depending on both the structure of the carbamate substituent as well as the position of guanidines-N substitution. The velocity of enzyme carbamoylation was analyzed and showed similar behavior to physostigmine. Phenolic compounds formed after carbamate transfer to the active site of cholinesterases showed additional neuroprotective properties on a hippocampal neuronal cell line (HT-22) after glutamate-induced intracellular reactive oxygen species generation.
- Darras, Fouad H.,Kling, Beata,Sawatzky, Edgar,Heilmann, J?rg,Decker, Michael
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- Divergent 2-Chloroquinazolin-4(3H)-one Rearrangement: Twisted-Cyclic Guanidine Formation or Ring-Fused N-Acylguanidines via a Domino Process
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A highly efficient 2-chloroquinazolin-4(3H)-one rearrangement was developed that predictably generates either twisted-cyclic or ring-fused guanidines in a single operation, depending on the presence of a primary versus secondary amine in the accompanying diamine reagent. Exclusive formation of twisted-cyclic guanidines results from pairing 2-chloroquinazolinones with secondary diamines. Use of primary amine-containing diamines permits a domino quinazolinone rearrangement/intramolecular cyclization, gated through (E)-twisted-cyclic guanidines, to afford ring-fused N-acylguanidines. This scalable, structurally tolerant transformation generated 55 guanidines and delivered twisted-cyclic guanidines with robust plasma stability and an abbreviated total synthesis of an antitumor ring-fused guanidine (4 steps, 55 % yield).
- Yan, Gang,Zekarias, Bereket L.,Li, Xiaoyu,Jaffett, Victor A.,Guzei, Ilia A.,Golden, Jennifer E.
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p. 2486 - 2492
(2020/02/13)
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- Synthesis of 2,4-diaminoquinazolines and tricyclic quinazolines by cascade reductive cyclization of methyl N -cyano-2-nitrobenzimidates
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An efficient route to N4-substituted 2,4-diaminoquinazolines has been developed by employing tandem condensation of cyanoimidate-amine and reductive cyclization in iron-HCl system. This method is tolerant of a following intramolecular N-alkylation and produces two fused heterocycles in a one-pot procedure. This protocol is a facile two-step synthesis of tricyclic quinazolines, which is effected by potent cyanoimidation and tandem reductive cyclization from 2-nitrobenzaldehydes. Moreover, the forming process of tricyclic quinazolines has been investigated from the ring-opening/ring-closing cascade point of view. It is found that the preparation of tricyclic quinazolinones in good yields relies on the selective hydrolysis of tricyclic quinazolines in base or acid system.
- Yin, Ping,Liu, Nan,Deng, Yu-Xing,Chen, Yue,Deng, Yong,He, Ling
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p. 2649 - 2658
(2012/06/01)
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- Radical synthesis of guanidines from N-Acyl cyanamides
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Chemical Equation Presented Center stage: Additions of nitrogen-centered radicals to cyanamide compounds provided the first radical synthesis of aromatic polycyclic guanidine derivatives (see scheme). Modular assembly of the substrates allows for a rapid increase of the molecular complexity of scaffolds, which have potential applications for medicinal chemistry.
- Larraufie, Marie-Helene,Ollivier, Cyril,Fensterbank, Louis,Malacria, Max,Lacote, Emmanuel
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supporting information; experimental part
p. 2178 - 2181
(2010/06/18)
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- Synthesis of novel 2,3-substituted quinazolin-4-ones by condensation of alkyl or aromatic diamines with 5-(N-arylimino)-4-chloro-5H-1,2,3-dithiazoles
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The work described in this paper is a further example of the utility of Appel's salt in the conception of novel heterocyclic rings. We confirmed that primary alkyldiamines may react easily with the methyl N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)-anthrani
- de Fatima Pereira, Maria,Thiéry, Valérie,Besson, Thierry
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p. 847 - 854
(2007/10/03)
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- Study on organic nitrates. Part VII. New nitrate derivatives of 6-oxo-1,2,3,4-tetrahydro-6H-pyrimido [2,1-b] quinazoline. Potential NO donors
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A series of potential NO donors derivatives of 6-oxo-1,2,3,4-tetrahydro-6H-pyrimido[2,1-b]quinazoline with the structure of organic nitrates was obtained. They were tested in vitro potentiometrically in the reaction with sulfhydryl compound L-cysteine hydrochloride monohydrate.
- Korzycka
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p. 557 - 563
(2007/10/03)
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- Synthesis and pharmacological investigations of new 6-oxo-1,2,3,4-tetrahydro-6H-pyramido[2,1-b]quinazoline derivatives
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The synthesis and biological activity of a series of 6-oxo-1,2,3,4-tetrahydro-6H-pyrimido[2,1-b]quinazoline is reported. Pharmacological investigations have shown that the compounds exert depressive action on the central nervous system and exhibit neuroleptic activity.
- Korzycka,Szadowska,Pakulska
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p. 815 - 819
(2007/10/02)
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- Synthesis of 4(3H)-Quinazolinones from Derivatives of Methyl 2-Isothiocyanatobenzoate
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Ethyl N-((2-methoxycarbonylphenyl)thiocarbamate (2), N-(2-ethoxycarbonylphenyl)-4-methoxythiobenzamide (3b), and 2-(4-methoxyphenyl)4H,-3,1-benzothiazin-4-one (4a), react with nucleophilic reagents containing at least one primary amino group to yield a variety of 2-substituted and 2,4-disubstituted 4(3H)-quinazolinones, as well as some tricyclic and tetracyclic products.
- Dean, William D.,Papadopoulos, Eleftherios P.
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p. 1117 - 1124
(2007/10/02)
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