ChemInform Abstract: CYCLIZATION PRODUCTS OF 2-(3-CHLORO-4-METHYLBENZOYL)BENZOIC ACID BY POLYPHOSPHORIC ACID

1985 ◽  
Vol 16 (17) ◽  
Author(s):  
T. HAYASHI ◽  
T. TOKUMITSU ◽  
T. OKAMOTO ◽  
M. NISHIYAMA
1984 ◽  
Vol 49 (4) ◽  
pp. 992-1001 ◽  
Author(s):  
Jiří Urban ◽  
Antonín Dlabač ◽  
Martin Valchář ◽  
Miroslav Protiva

The 6-nitro derivative V, obtained by nitration of 3,4-dichlorobrombenzene, was transformed via the amine VI and nitrileVII to 2-bromo-4,5-dichlorobenzoic acid (IX). Its reaction with thiophenol in 3-methyl-1-butanol in the presence of potassium carbonate and catalytic amounts of copper and cuprous iodide afforded 4,5-dichloro-2-(phenylthio)benzoic acid (Xa) which was reduced to the alcohol XIa. The transformation to the homologous acid XIVa proceeded via noncharacterized intermediates XIIa and XIIIa. The cyclization with polyphosphoric acid at 150 °C resulted in 2,3-dichlorodibenzo[b,f]thiepin-10(11H)-one (XV) which was reduced to the alcohol XVI. Treatment with hydrogen chloride gave the unstable chloro derivative XVII whose substitution reaction with 1-(2-hydroxyethyl)piperazine led to the title compound II. Its dimethanesulfonate showed properties of a little toxic and noncataleptic tranquillizer. Because it does not influence the dopamine metabolism in rat brain in a rather high dose, it cannot be considered a neuroleptic.


2011 ◽  
Vol 217-218 ◽  
pp. 768-773 ◽  
Author(s):  
Hai Hui Liu ◽  
Ning Wang ◽  
Li Chen Hou ◽  
Wei Wei Peng ◽  
Yan Mei Jin ◽  
...  

Pristine multi-walled carbon nanotubes (P-MWNTs) were functionalized with 4-substituted benzoic acid via ‘‘direct’’ Friedel-Crafts acylation in mild reaction medium of polyphosphoric acid (PPA)/phosphorous pentoxide (P2O5). Raman spectroscopy, thermogravimetric analysis, transmission electron microscopy were applied in this paper to demonstrate that multi-walled carbon nanotubes inherently have functional groups on their surfaces as a result of the reaction. The overall evidence indicates that the 4-substituted benzoic acid functionalization of carbon nanotube can be achieved without oxidation as pre-treatment. Thus, aryl carbonyl moieties with different length of 4-substituted alkyl acyl amine functionalized MWNTs(F-MWNTs) can be synthesized simply, without disrupting the primary structures of the nanotubes.


2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Camelia Elena Stecoza ◽  
Miron Teodor Caproiu ◽  
Constantin Draghici ◽  
Corina Ilie ◽  
Ileana Cornelia Chirita

The aim of the present paper was the synthesis and chemical characterization of some original compounds with dibenzo[b,e]thiepine structure. The synthesis of the new compounds was performed in several stages. Thus, by reaction of phtalide with thiophenol potassium salt, we obtained the 2-phenylthiomethyl-benzoic acid. The acid was cyclized with polyphosphoric acid to the desired 6,11-dihydrodibenzo[b,e]thiepin-11(6H)-one, converted afterwards to the corresponding oxime and subsequently to the O-acyloximino-dibenzo[b,e]thiepins by acylation with various substituted benzoic acid chlorides. The oxidation of O-acyloximino-dibenzo[b,e]thiepins with hydrogen peroxide afforded the corresponding sulfones. The new compounds, four O-acyl-oximino-dibenzo[b,e]thiepins, and four O-acyl-oximino-dibenzo[b,e]thiepin-5,5-dioxides, have been characterized by their physical constants (melting point, solubility) and their structures and purity were confirmed by elemental analysis, and spectral analysis (IR, 1H-NMR, 13C-NMR).


1984 ◽  
pp. 2011-2014 ◽  
Author(s):  
Takayuki HAYASHI ◽  
Takao TOKUMITSU ◽  
Tsuyoshi OKAMOTO ◽  
Mitsue NISHIYAMA

Author(s):  
Stelian Florea ◽  
Anca Nicolae ◽  
Ovidiu Maior

The new ring systems, benzo[e]dibenzofuro[2,3-b]oxepin-5(14H)-one and benzo[e]dibenzofuro[2,1-b]oxepin-5(14H)-one were obtained by cyclizing of 2-(2-dibenzoftuyloxymethyl)benzoic acid in the presence of polyphosphoric acid ester.By cyclization of the 2-(1-methoxy-2-dibenzofuryloxymethyl) benzoic acid was obtained benzo[e]dibenzofuro[2,3-b]-oxepin-12-methoxy-5-one with a indubitable structure. The structure of the new compounds was proved by means of 1H-and 13C-NMR spectra.


Author(s):  
W. E. Lee

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.


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