Somaia M. Abdel-Kariem

Cleavage of Diethyl Chromonyl α-Aminophosponate with Nitrogen and Carbon Nucleophiles: A Synthetic Approach and Biological Evaluations of a Series of Novel Azoles, Azines, and Azepines Containing α-Aminophosphonate and Phosphonate Groups

Abstract A convenient synthetic approach leading to a series of novel substituted azoles, azines, and azepines linked to the α-aminophosphonate moiety was achieved. The methodology depends on ring opening and ring closure (RORC) of the chromone ring of diethyl chromonyl α-aminophosphonate 1 via its reaction with nitrogen nucleophiles such as primary amines and 1,2-, 1,3-, and 1,4-bi-nucleophiles in ethanolic sodium ethoxide. Also, treatment of compound 1 with some acyclic and cyclic active methylene compounds under the same reaction conditions afforded interesting novel isolated and fused pyridine systems bearing phosphonate groups at the α-position. The screening of antimicrobial activity for the synthesized compounds indicates that connection of pyrazole, oxazepine, and benzodiazepine rings with α-aminophosphonate moiety exhibited good antimicrobial effects. Also, evaluation of their antioxidant properties shows that the compounds having 1,5-benzoxazepinyl and 1,5-benzodiazepinyl units in combination with α-aminophosphonic diester moiety are the most powerful antioxidant agents. GRAPHICAL ABSTRACT

Synthesis of Biologically Active 4-Oxo-4H-Chromene Derivatives Containing Sulfur-Nitrogen Heterocycles

The synthesis of 4-oxo-4H-chromenes containing sulfur-nitrogen heterocyclic rings as well as their biological activities are reviewed.

SYNTHETIC METHODS FOR PHOSPHORUS COMPOUNDS CONTAINING PYRAZOLE RINGS

Abstract – The present review considers all the literature data on methods developed for the synthesis of phosphorus compounds containing pyrazole rings starting from their appearance up to the 2011. The described methods for the synthesis of phosphorus compounds containing pyrazole rings can be divided into three routes: a) direct phosphorylation of pyrazole rings, b) ring closure of acyclic phosphorus compounds with different reagents into phosphono-pyrazoles and c) cyclization of side functional groups to give isolated and fused phosphorus heterocyclic systems containing pyrazole rings.

Reaction of 2-cyano[(4-oxo-4H-chromen-3-yl)methylidene]acetohydrazide with phosphorus reagents: Synthesis and evaluation of anticancer activities of some novel 1,2-azaphospholes, 1,2,3-diazaphospholidine, and 1,3,2-diaza-phosphinanes bearing a chromone ring

ABSTRACT A series of 1,2-azaphospholes, 1,2,3-diazaphospholidine, 1,3,2-diaza-phosphinanes bearing a chromone ring as well as dialkyl pyrazolopyrimidine phosphonates have been synthesized from treatment of multifunctional 2-cyano[(4-oxo-4H-chromen-3-yl)methylidene]acetohydrazide (2), some phosphorus reagents such as phosphonic acid and its esters, and phosphorus sulfides as well as phosphorus halides in dry dioxane. The isolated products were evaluated for their anticancer activities and on the expression of vascular endothelial growth factor (VEGF) inhibition. Among the isolated products, compounds 3 and 10 exhibited higher effect against breast cancer cells than the reference drug and on the expression of VEGF inhibition. GRAPHICAL ABSTRACT

Synthesis and antioxidant properties of some novel 1,3,4,2-oxadiazaphosphepino[6,7-c]quinolinones and pyrazolo[3,4:4′,3′]quinolino[5,1-c][1,4,2]oxazaphosphinine

GRAPHICAL ABSTRACT ABSTRACT A series of novel 1,3,4,2-oxadiazaphosphepino[6,7-c]quinolinones 3–5, 9, and 11 have been synthesized from treatment of 4-hydroxy-1-methyl-3-[1-(2-phenylhydrazinylidene)ethyl]quinolin-2(1H)-one (2) with some phosphorus sulfides, diethyl phosphite and phenyl phosphonic dichloride, respectively, in dry dioxane. Also, reaction of hydrazone 2 with tris(2-chloroethyl)phosphite under the same reaction conditions gave pyrazolo[3,4:4′,3′]quinolino[5,1-c][1,4,2]oxazaphosphinine 10. However, when hydrazone 2 was treated with phosphonic acid, phosphorus tribromide or phosphorus oxychloride, 3,5-dimethyl-1-phenyl-1,5-dihydro-4H-pyrazolo[4,3-c]quinolin-4-one (7) was isolated in all cases. The compounds were evaluated for their antioxidant activities. Among the synthesized compounds, 1,3,4,2-oxadiazaphosphepino[6,7-c]quinolinone-2-sulfide 5 and its analogue 2-oxide 11 exhibited higher antioxidant activities than the standard antioxidant.

Electron Impact Ionization Mass Spectra of Organophosphorus Compounds Part IV: Mass Fragmentation Modes of Some Diethyl [(Alkyl/Arylamino)(6-Methyl-4-Oxo-4H-Chromen-3-YL)Methyl]Phosphonates

GRAPHICAL ABSTRACT Abstract Electron ionization mass fragmentation pathways of four synthetic organophosphorus compounds, belonging to α-chromonyl-α-aminophosphonates, were proposed on the basis of their low-resolution mass spectrometry and referring to reported results with the aim of obtaining a better understanding of their fragmentation processes. The intensity of recorded molecular ion peaks was weak to moderate values. The α-aminophosphonate moieties demonstrated different fragmentation modes in each compound. Chromone rings underwent known a retro Diels–Alder fragmentation process.

Facile synthesis of novel 6-methyl-5-phenyl-2-sulfido-1,2,3,5-tetrahydro-4H[1,2] oxazolo[4′,5′:5,6]pyrano[2,3-d][1,3,2]diazaphosphinines

ABSTRACT A number of 6-methyl-5-phenyl-2-sulfido-1,2,3,5-tetrahydro-4H[1,2]oxazolo[4′,5′: 5,6]pyrano[2,3-d][1,3,2]diazaphosphinines 4–11 were synthesized via an interaction of tetraphosphorus decasulfide and Lawesson’s reagent under different conditions with 6-amino-3-methyl-4-phenyl-4H-pyrano[3,2-d][1,2]oxazole-5-carbonitrile (3). The reaction mechanisms for these products were discussed. Structures of the newly synthesized products were established on the basis of elemental analysis and spectral data. GRAPHICAL ABSTRACT

Reaction of 2-hydroxy- N ′-[(4-oxo-4 H -chromen-3-yl)methylidene]benzohydrazide with some phosphorus reagents. Synthesis and evaluation of anticancer activity of novel α-hydrazinophosphonic acid, 1,4,5,2λ 5 -oxadiazaphosphinines, and 1,3,2λ 5 -benzoxazaphosphinines bearing a chromone ring

Novel 1,4,5,2-Oxadiazaphosphinines, 1,3,2-benzoxazaphosphinines, and α-hydrazinophosphonic acid bearing a chromone ring were obtained by reactions of 2-hydroxy-N′-[(4-oxo-4H-chromen-3-yl)-methylidene]benzohydrazide with some phosphorus reagents such as phosphonic acid and its esters, phosphorus sulfides, and phosphorus halides. The synthesized compounds were evaluated for their anticancer activity against four cancer cell lines. Two compounds exhibited high effects against MCF-7 breast cancer cells and on the expression of VEGF inhibition.

Electron ionization mass spectra of organophosphorus compounds Part V: Mass fragmentation modes of some azolyl, azinyl, and azepinyl phosphonates as cyclic α-aminophosphonates

GRAPHICAL ABSTRACT ABSTRACT Mass fragmentation pathways of eight synthetic organophosphorus compounds, belonging to azolyl, azinyl, and azepinyl phosphonates as cyclic α-aminophosphonates 1a,b–4a,b were investigated by electron impact mass spectrometry with the aim of obtaining a better understanding of their fragmentation processes. The intensity of the recorded molecular ion peaks showed moderate values. Compounds 1a,b–3a,b have almost identical fragmentation routes via easy elimination of phosphonate groups which can be fragmented into the cation PO2 as base peaks. On the contrary, compounds 4a,b started their fragmentation via removal of 4-chlorophenyl moieties.