19768-02-6Relevant articles and documents
Synthesis of Novel Heteromacrocyclic Compounds from (E,E)-1,2-Diketone Dioximes and Dichloromethane
Hosokawa, Takahiro,Ohta, Toshiyuki,Murahashi, Shun-Ichi
, p. 7 - 8 (1982)
(E,E)-1,2-Diketone dioximes, when treated with base in the presence of a phase transfer catalyst in dichloromethane, afford new heteromacrocyclic compounds in which oxime units are sequentially linked by methylene bridges.
Synthesis and cytotoxic evaluation of combretafurazans
Tron, Gian Cesare,Pagliai, Francesca,Del Grosso, Erika,Genazzani, Armando A.,Sorba, Giovanni
, p. 3260 - 3268 (2007/10/03)
Combretastatin A-4 is an antitumoral and antitubulin agent that is active only in its cis configuration. In the present manuscript, we have synthesized cis-locked combretastatins embodying a furazan ring (combretafurazans). To achieve this, we have developed a new strategy that exploits the dehydration of vicinal dioximes using the Mitsunobu reaction. Among the advantages of following such a strategy are the mild conditions used for the construction of the diarylfurazan derivatives, allowing for the presence of highly functionalized substrates and deactivated aromatic rings. Combretafurazans are more potent in vitro cytotoxic compounds compared to combretastatins in neuroblastoma cells, yet maintaining similar structure-activity relationship and pharmacodynamic profiles.
Triphenylmethyl Phenylcyanomethylenenitronate: Formation and Thermolysis
Boyer, Joseph H.,Manimaran, Thankiavelu,Ramakrishnan, Vayalakkavoor T.
, p. 2163 - 2170 (2007/10/02)
The previously reported formation of carbon dioxide, α,α'-bis(tritylazo)stilbene (4), benzonitrile N-oxide (5), trityl isocyanate (6), and C33H25N3O (11) from a mixture ot trityl chloride and silver phenylcyanomethylenenitronate in toluene is now attributed to the initial formation at -20 deg C of trityl phenylcyanomethylenenitronate (3) and its dissociations at 5 deg C.The ester (3) was characterized by conversion into bromonitrophenylacetonitrile (7) by treatment with bromine, to p-nitrobenzoyl cyanide (8) by treatment with dinitrogen tetraoxide, to trityl alcohol by hydrolysis, and to a mixture of trityl alcohol and trityl peroxide by exposure to the atmosphere.The bisazostilbene (4) (18percent) and C33H25N3O, identified by X-ray crystallographic analysis to be 4,5-diphenyl-1-triphenylmethoxy-1,2,3-triazole (11) (24percent), were obtained from the nitronate ester (3) in toluene at 5 deg C; the nitrile oxide (5) and the isocyanate (6) were obtained in low yields from the ester (3) in dimethyl sulphoxide at 25 deg C.Hydrolysis converted the triazole (11) into 1-hydroxy-4,5-diphenyl-1,2,3-triazole (12) and trityl alcohol.Silver p-bromophenylcyanomethylenenitronate and trityl chloride afforded α,α'-bis-(tritylazo)-p,p'-dibromostilbene and its thermolysis product, p,p'-dibromodiphenylacetylene.Fragmentation of the ester (3) in presence of added phenyl isocyanate gave the bisazo compound (4) and 3,4-diphenyl-1,2,4-oxodiazol-5-one (18).A similar mixture stored at -20 deg C gave the triazole (11) and the oxadiazolone (18).Aroyl nitrile oxides as well as phenyl isocyanate suppressed the formation of the red bisazostilbene (4).The intermediacy of the N-trityl imine (14) of 4H-3-phenyl-1,2-oxazet-4-one-2-oxide in the thermolysis of the nitronate (3) was discussed.