نتایج جستجو برای: 3 dicarbonyl compounds
تعداد نتایج: 1987990 فیلتر نتایج به سال:
Abstract The base-catalyzed reaction of diethyl 1,3-acetonedicarboxylate with 2-hydroxybenzylidene indenediones was studied. provides a facile and expeditious protocol for the synthesis natural product inspired fluorenone-fused coumarins in good to very yields. This process resembles combination domino Michael–intramolecular Knoevenagel–aromatization–lactonization reactions single step. Althoug...
A series of imidazo[2,1-b]thiazoles bearing pyrazole moieties 4-6(a-c) was synthesized through the reaction of 6-hydrazinylimidazo[2,1-b]thiazoles 3a-c with different β-dicarbonyl compounds. Eleven compounds were screened at the National Cancer Institute (NCI), USA for anticancer activity at a single dose (10 μM). The in vitro anticancer evaluation revealed that compounds 2a and 4-6(a) exhibite...
A methodology for selective transformations of ketones, esters, Weinreb amides, and nitriles in the presence of aldehydes has been developed. The use of a combination of PPh(3)-trimethylsilyl trifluoromethanesulfonate (TMSOTf) promotes selective transformation of aldehydes to their corresponding, temporarily protected, O,P-acetal type phosphonium salts. Because, hydrolytic work-up following ens...
Tamoxifen is the standard adjuvant endocrine therapy for estrogen-receptor positive premenopausal breast cancer patients. However, tamoxifen resistance is frequently observed under therapy. A tamoxifen resistant cell line has been generated from the estrogen receptor positive mamma carcinoma cell line MCF-7 and was analyzed for putative differences in the aldehyde defence system and accumulatio...
A series of substituted ethyl 1-[(tert-butoxycarbonyl)amino]-2-methyl-5- (1-methyl-1H-indol-3-yl)-4-[(1-methyl-1H-indol-3-yl)carbonyl]-1H-pyrrole-3-carboxylates were prepared in excellent yields (82-98%) by one-pot reactions between β-dicarbonyl compounds 12a-e and 1,2-diaza-1,3-diene (DD) 13. Derivatives 10a,c-e, deazaanalogues of the bis-indole alkaloid topsentin, screened by the National Can...
quinolines, an important class of potentially bioactive compounds, have been synthesized by treatment of o-aminoarylketones and carbonyl compounds utilizing niobium (v) chloride / polyethylenglycole(nbcl5.peg) and niobium(v)chloride (nbcl5) as available and inexpensive catalysts. the quinoline derivatives were prepared in glycerol, an excellent solvent in terms of environmental impact, with hig...
an efficient and green protocol for the synthesis of pyrazoles derivatives by one-pot reaction of different 1,3-dicarbonyl compounds with hydrazines/hydrazides has been developed using nano-sulfated zirconia, nano-structured zno, nano-g-alumina and nano-zsm-5 zeolites, as the catalyst. the optical properties of the nano-structured catalysts and organic molecules were studied. the advantages of ...
Abstract A highly efficient and catalyst-free protocol is reported for the synthesis of quinoxalines via classical cyclocondensation reaction between aryldiamines dicarbonyl compounds. Remarkably simple green conditions employing methanol as solvent afforded medium to excellent yield after only one-minute time at ambient temperature. The allow least 10 gram scale should be a preferred starting ...
Recently it has been demonstrated that the typical aroma of oxidative spoiled white wine are related with the presence of methional and phenylacetaldehyde, substances accountable respectively for the “boiled-potato” and “honey-like” odour notes with threshold values of 0.5 μg/L and 25 μg/L . These compounds can be formed by the direct oxidation of the respective alcohol or via Strecker degradat...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید