Photography. Processing chemicals. Specifications for anhydrous potassium carbonate

2015 ◽  

2019 ◽  
Vol 4 (4) ◽  
pp. 232-235
Author(s):  
H.M. Naveena Kumari ◽  
Manjunath Harihara Mathada ◽  
Mahesh Kumar ◽  
K.T. Suda ◽  
K.M. Basavaraja

Present work reports the biologically important benzofuran aryl ureas and carbamates. The benzofuran ring was formed by reacting bromo salicylaldehyde with diethyl bromomalonate in presence of dry acetone and anhydrous potassium carbonate to obtain 5-bromo-2-ethyl carboxylate (1). The obtained ester (1) was converted into corresponding hydrazide (2) by treating with hydrazine hydrate in ethanol. Compound 2 was then converted into 5-bromobenzofuran-2-carbonyl azide (3) by treating it with sodium nitrite in dioxane and acetic acid. The compound 3 is converted into 5-bromobenzofuranyl aryl ureas (4a-e) after treating primary amines and anhydrous toluene. 5-Bromobenzofuranyl aryl carbamate (5) and ethyl carbamate (6) were also synthesized by treating compound 3 with substituted phenol in toluene and ethanol respectively. All the compounds were characterized by NMR, IR and screened for antimicrobial activities.



1994 ◽  
Vol 59 (11) ◽  
pp. 2357-2374 ◽  
Author(s):  
Erich Lippert ◽  
Karel Mocek ◽  
Emerich Erdös

Results are presented of an experimental kinetic study of the heterogeneous reaction between gaseous sulfur dioxide and solid anhydrous potassium carbonate. The measurements were carried out in an all glass kinetic flow apparatus with nitrogen as the carrier gas and a fixed bed of the solid working in the differential regime at atmospheric pressure and a temperature of 423 K (150 °C). The reaction course was studied in dependence on the partial pressures of sulfur dioxide (pSO2) and water vapour (pH2O) in concentration ranges pSO2 = 13 - 430 Pa and pH2O = 0 - 2 100 Pa. In the reaction, water vapour acts as a gaseous catalyst. Based on the experimental data, the corresponding kinetic equation was found together with the numerical values of the relevant rate and equilibrium adsorption constants.



2008 ◽  
Vol 63 (12) ◽  
pp. 1431-1437 ◽  
Author(s):  
Raafat M. Shaker ◽  
Mohamed Abd Elrady

A series of 6,7,8,10-tetrahydropyrimido[5,4-b]quinolin-2,4,9-(1H,3H,5H)-triones 6 were synthesized through one-pot condensation of 5-aminouracil, aldehydes and dimedone in DMF under microwave irradiation without catalyst. The products 6a, d were oxidized to the 7,8-dihydro-pyrimido- [5,4-b]quinolin-2,4,9-(1H,3H,6H)-triones 11a, b. Treatment of 6a, d and/or 11a, b with ethyl iodide in the presence of anhydrous potassium carbonate gave the ethylated derivatives 12a, b and 13a, b, respectively. The structures of the products were confirmed by elemental analyses, IR, MS, 1H, and 13C NMR spectra.



1996 ◽  
Vol 7 (4) ◽  
pp. 213-220 ◽  
Author(s):  
A. Mai ◽  
M. Artico ◽  
S. Massa ◽  
R. Ragno ◽  
A. De Montis ◽  
...  

The synthesis of 5-methyl-2-thienylketopolymethylene oxyphenyl 4,5-dihydro-2-(alkyl)oxazoles was accomplished by the assembly of two synthones, namely 1-(5-methyl-2-thienyl)-7-hydroxy-1-heptanone (or 1-(5-methyl-2-thienyl)-5-chloro-1-pentanone) and 4-[4,5-dihydro(alkyl)oxazol-2-yl]phenol, in the presence of diethyl azodicarboxylate(DEAD)-triphenyl phosphine (or sodium iodide and anhydrous potassium carbonate). Eighteen new disoxaril analogues were synthesized by the above procedure and tested in vitro against several rhino and enteroviruses. With a few exceptions, all test derivatives were more potent than WIN 51711 when assayed against HRV-14, and as potent as WIN 51711 against HRV-2, but none of them inhibited the other HRV serotypes. Among the various derivatives, two compounds showed the same wide spectrum activity of WIN 51711 against several rhino, and enteroviruses, but were at least 10-fold less toxic.







1988 ◽  
Vol 41 (2) ◽  
pp. 183 ◽  
Author(s):  
DSC Black ◽  
RJ Strauch

The 2,4-diaryl-1-pyrroline 1-oxides (4) can be converted into the related 2H-pyrrole 1-oxides (5) by treatment with N-bromosuccinimide and anhydrous potassium carbonate. Similar treatment of the 1-pyrroline 1-oxide (6) yielded the succinimido-substituted pyrroline (7). Selenium dioxide oxidation of the tetramethyl nitrone (8) under various conditions gave mixtures containing the compounds (10)-(12). Neither process provides a general conversion of 1-pyrroline 1-oxides into 2H-pyrrole 1-oxides.



2019 ◽  
Vol 816 ◽  
pp. 55-60
Author(s):  
Z.I. Kurdanova ◽  
Azamat Zhansitov ◽  
Azamat L. Slonov ◽  
K.T. Shakhmurzova ◽  
A.E. Baykaziev ◽  
...  

Polyether ether ketones based on 4,4'-difluorobenzophenone and hydroquinone in sulfolane medium in the presence of anhydrous potassium carbonate were synthesized by the method of high-temperature polycondensation. The rheological, thermal, electrical and physical-mechanical properties are investigated. It is shown that, at processing temperatures, the molecular weight of polyether ether ketones synthesized in sulfolane increases, apparently due to the branching processes of the polymer chain.



2011 ◽  
Vol 52 (39) ◽  
pp. 5020-5024 ◽  
Author(s):  
Rina Mondal ◽  
Arpita Das Gupta ◽  
Asok K. Mallik


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