2423-66-7Relevant articles and documents
Hypoxia-selective agents derived from 2-quinoxalinecarbonitrile 1,4-di-N- oxides. 2
Monge,Martinez-Crespo,De Cerain,Palop,Narro,Senador,Marin,Sainz,Gonzalez,Hamilton,Barker
, p. 4488 - 4494 (1995)
Hypoxic cells are an important target for antitumor therapy because tumors are typically characterized by such cells. Virtually all tumors which are present as solid masses contain hypoxic cells, while normal cells generally have an adequate supply of oxygen. Accordingly, antitumor agents can be made selective for tumors by virtue of high activity under hypoxic conditions. The initial purpose of this work was to determine the influence of different groups in position 3. Thus, the synthesis of some 3-NH-substituted derivatives (2a, 3a, 4a) starting from 3-amino-2-quinoxalinecarbonitrile 1,4- di-N-oxide (1a) is described. Reductive deamination of compounds 1a-k provides the 2-quinoxalinecarbonitriles 5a-k, which are more potent, while selectivity is maintained or increased in some derivatives. The compound 7- (4-nitrophenyl)-2-quinoxalinecarbonitrile 1,4-di-N-oxide (5k) is 150-fold more potent than tirapazamine (3-amino-1,2,4-benzotriazine 1,4-di-N-oxide), which has been used as a standard. Three derivatives (5g,i,k) show a hypoxic cytotoxicity ratio (HCR) ≥ 200, better than that of tirapazamine (HCR = 75) in V79 cells. Replacement of the 3-amino group by chlorine affords the potent but nonselective 3-chloro derivatives 6a-k showing similar toxicities under both aerobic and hypoxic conditions. These compounds were used as intermediates for the synthesis of a new series of water-soluble compounds derived from 3-[[(N,N-dialkylamino)alkyl]amino]-2-quinoxalinecarbonitrile 1,4-di-N-oxides 10a-i and 11a-i. The 7-chloro and the 7-trifluoromethyl derivatives 10b,f have demonstrated high potency (0.4 and 0.3 μM) and excellent selectivity (HCR = 250 and 340). Several 7-chloro analogues, 12b, 13b.1,b.2, and 14b, and the dimer 16b have been prepared and evaluated in order to determine the optimum lateral chain in position 3, which appears to be the [(N,N-dimethylamino)propyl]amino moiety.
Bromination of quinoxaline and derivatives: Effective synthesis of some new brominated quinoxalines
U?ar, Sefa,E?siz, Sel?uk,Da?tan, Arif
, p. 1618 - 1632 (2017/03/08)
The synthesis of brominated quinoxaline derivatives starting from several kinds of quinoxaline by different bromination strategies was studied. First the synthesis of some brominated quinoxalines was accomplished along with the development of an alternative and effective synthesis of some known compounds. A new, clean, and effective synthetic method for selective reduction of quinoxaline to 1,2,3,4-tetrahydroquinoxaline was also developed. The products obtained were characterized by means of NMR spectroscopy, elemental analyses, and mass spectrometry.
Catalytic N-oxidation of tertiary amines on RuO2NPs anchored graphene nanoplatelets
Gopiraman, Mayakrishnan,Bang, Hyunsik,Babu, Sundaram Ganesh,Wei, Kai,Karvembu, Ramasamy,Kim, Ick Soo
, p. 2099 - 2106 (2014/06/24)
Ultrafine ruthenium oxide nanoparticles (RuO2NPs) with an average diameter of 1.3 nm were anchored on graphene nanoplatelets (GNPs) using a Ru(acac)3 precursor by a very simple dry synthesis method. The resultant material (GNPs-RuO2NPs) was used as a heterogeneous catalyst for the N-oxidation of tertiary amines for the first time. The transmission electron microscopy (TEM) images of the GNPs-RuO2NPs showed the excellent attachment of RuO2NPs on GNPs. The loading of Ru in GNPs-RuO2NPs was 2.68 wt%, as confirmed by scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The X-ray photoelectron spectrum (XPS) and the X-ray diffraction pattern (XRD) of GNPs-RuO 2NPs revealed that the chemical state of Ru on GNPs was +4. After the optimization of reaction conditions for N-oxidation of triethylamine, the scope of the reaction was extended to various aliphatic, alicyclic and aromatic tertiary amines. The GNPs-RuO2NPs showed excellent catalytic activity in terms of yields even at a very low amount of Ru catalyst (0.13 mol%). The GNPs-RuO2NPs was heterogeneous in nature, chemically as well as physically, very stable and could be reused up to 5 times. The Royal Society of Chemistry 2014.
