نتایج جستجو برای: bromine compounds
تعداد نتایج: 228559 فیلتر نتایج به سال:
The D-glucose derived aziridine carboxylate 5 was obtained from (E)-ethyl-6-bromo-1,2-O-isopropylidene-3-O-benzyl-5-deoxy-alpha-D-xylo-5-eno-heptofuranuronate 4 through conjugate addition of benzylamine and in situ intramolecular nucleophilic expulsion of bromine. The regioselective aziridine ring-opening, using water as a nucleophile, resulted in the alpha-hydroxy-beta-aminoester 6, which was ...
UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system. Brominated rugulovasines were also detected when the microbial incubation medium was supplemented with br...
Hydroxy acid, oxidation, bromine The oxidation of glycollic, lactic, a-hydroxybutyric, and 2-phenyllactic acids by aque ous bromine has been studied. The reaction is of first order with respect to the oxidant and the anion of the hydroxy acid respectively. The active oxidising species is molecular bromine. The oxidation of ci,a-dideuterioglycollic acid indicated a kinetic isotope effect, ^h /^...
محافظت و محافظت زدایی از گروه های کربونیل همواره مورد مهمی در علم شیمی قلمداد شده است. روش معمول سنتز انامین ها به عنوان یک گروه محافظ کربونیل معایبی دارد که از جمله آنها استفاده از حلال های به شدت سمی و خطرناک مانند بنزن و تولوئن و نیز زمان طولانی واکنش است. برای رفع این مورد طی انجام این پژوهش سعی بر آن داشتیم که با استفاده از شرایط بدون حلال و بهره گیری از کاتالیزور اسید های لوئیس روش ساخت ...
The effect of the electron-withdrawing fluorine, chlorine, and bromine atoms on electronic optical properties crystalline tetrathienoanthracene tetrathionoacridine derivatives were investigated by dispersion-corrected density functional theory. Our results also show that position sulfur substitution CH group with a nitrogen atom can improve charge transport title compounds. In addition, slight ...
2-Alkylthio-6-aminobenzothiazoles and their 6-N-substituted derivatives 3-(2-alkylthio-6-benzothiazolylaminomethyl)-2-benzothiazolineth iones and 3-(2-alkylthio-6-benzothiazolylaminomethyl)-6-bromo-2-benzothia zolinones inhibit photosynthetic processes in spinach chloroplasts and the chlorophyll production in Chlorella vulgaris. The inhibitory activity depends on the alkyl chain length of the t...
Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density...
An overview of the known methods introducing selenium under action elemental into structures various saturated, unsaturated, and heteroaromatic selenacycles containing C–Se, N–Se, B–Se, Ge–Se P–Se bonds is presented. These include metal, iodine, bromine or chlorine exchange for direct cyclization 1-(2-bromoaryl)benzimidazoles, polyunsaturated hydrocarbons, acetylenes, propargylic amines, 3-halo...
Five ethyl (5-alkyl-2-amino-1,3-thiazol-4-yl) acetates (designated compounds 4a-e) incorporating octyl, decyl, dodecyl, tetradecyl, and hexadecyl alkyl chains, respectively, were prepared by reacting 4-alkyl-4-bromo-3-oxobutyric acid ethyl esters (3a-e) with thiourea in dried acetonitrile. Compounds 3a-e were synthesized by reacting alkylated ethyl acetoacetates with bromine. The newly synthesi...
Series of the 2-unsubstituted and 2-(4-chlorophenyl)-substituted 4-anilino-6-bromoquinazolines and their 6-(4-fluorophenyl)-substituted derivatives were evaluated for in vitro cytotoxicity against MCF-7 and HeLa cells. The 2-unsubstituted 4-anilino-6-bromoquinazolines lacked activity, whereas most of their 2-(4-chlorophenyl) substituted derivatives were found to exhibit significant cytotoxicity...
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