نتایج جستجو برای: cyclization of time
تعداد نتایج: 21267950 فیلتر نتایج به سال:
The cyclization of b-anilino propionic acids in the presence of polyphosphoric acid (PPA) afforded the 2,3-Dihydroquinoline-4-(1H)-ones in good yields. N,N'-bis(2-carboxyethyl)-4-methyl-1,2-diaminobenzene (7) is cyclized under this condition to produce the 1,5-diaza-2,3,6,7-tetrahydro-4-methyl-pheranthrene-4,8-dione(bis-quinolone) (8).
Reaction of 2-hydrazinocarbonyl-3-chloro-5-phenoxy-benzo[b] thiophene with different substituted phenyl isothiocyanate gave N-substituted arylthiosemi-carbazide derivatives (1a-h). 1,3,4-Thiadiazole derivatives (2a-h) were prepared by the cyclization of arylthiosemicarbazides (1a-h) with concentrated sulphuric acid. All the compounds were screened for their antitubercular activity against Mycob...
A novel cyclization process of 2,3-bis(trimethylsilyl)buta-1,3-diene with various acyl chlorides in the presence of aluminium trichloride affords 2,5-disubstituted or 2,3,5-trisubstituted furans in short reaction time; a subsequent acylation process of the furan ring occurs if the reaction time is prolonged.
Condensation and cyclization of 5-hydroxy- 1,2,4- thiadiazol-2-yl hydrazine 1 with pyruvic acid, phenacyl bromide, propargyl bromide and ally1 bromide afforded compounds 2,5,7 3, 4 ,6 and 8 respectively, Reaction of 1 with epichforohydrine afforded 4-hydroxy-N-[5-hydroxy- 1 ,3,4-thiadiazoly1] pyrazolidine 9
1.1 introduction “i see translation as the attempt to produce a text so transparent that it does not seem to be translated. a good translation is like a pane of glass. you only notice that it’s there when there are little imperfections- scratches, bubbles. ideally, there shouldn’t be any. it should never call attention to itself.” “norman shapiro” (venuti, 1995:1) edward fitzgerald is the br...
b-cyclodextrin glucosyl transferase (b-cgtase) hydrolyses starch to produce b-cyclodextrin by transglycosylation (cyclization) activity. the conventional method for detection of b-cgtase activity is based on detecting starch hydrolysis by iodine staining. this method reveals all amylolytic enzymes, but can not discriminate them. in the present study, we introduce a new method for specific detec...
The C-terminal thioesterase (TE) domains from nonribosomal peptide synthetases (NRPSs) catalyze the final step in the biosynthesis of diverse biologically active molecules. In many systems, the thioesterase domain is involved in macrocyclization of a linear precursor presented as an acyl-S-enzyme intermediate. The excised thioesterase domain from the tyrocidine NRPS has been shown to catalyze t...
gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...
We report a new efficient gold-catalyzed cyclization of 1,6-diyne-4-en-3-ols to give naphthyl ketone derivatives under ambient conditions. The value of this cyclization is reflected by its applicability to a wide range of alcohol substrates.
diazotization of 3-amino-2-cmoro pyridine (3) in the presence of dithizone (5) gave dphenyl-2-phenylazo-4h-pyrid[o3 ,2-e] [1,3,4] thiadiazine (6). reaction of 2- chloro-3-nitropyridine (2, g=h) with (5) dfordd 4-phenyl -2-phenylazo -4hpyrido [2,3-el [1,3,4] thiadiazine (7). reduction of the latter with h gas in the presence of raney nickel gave the corresponding amino derivative (12). one pot c...
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