نتایج جستجو برای: disubstituted urea
تعداد نتایج: 40692 فیلتر نتایج به سال:
Rapid synthesis of symmetrical 1, 3disubstituted urea derivatives from biuret and different substituted anilines has been carried out in presence of Sodium chloride (NaCl) in dry media. Diverse substituted anilines were reacted with biuret in 2:1 molar ratio to give the corresponding urea derivatives. The reaction conditions were clement, solvent free, mild and the products were attained in goo...
An efficient two-step palladium catalysed synthesis of 2,5-disubstituted oxazoles is reported.
Reactions of N,N;-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N;-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]- thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene...
Herein we describe our efforts on the Lewis acid catalyzed stereoselective ring-opening of pentafulvene derived diazabicyclic olefins using various ortho-functionalized aryl iodides such as 2-iodoanilines, 2-iodophenols and 2-iodobenzene thiols to access trans-1,2 disubstituted alkylidenecyclopentenes. The scope of the reaction was also explored with a range of easily available aromatic and ali...
Bis-indolinone derivatives having either 2,6-disubstituted pyridine core (1a and 1b) or 1,10-disubstituted phenanthroline core (2a and 2b), already known to have antitumor activity, have been tested as potential G-quadruplex binders. Compounds 2a and 2b are able to selectively stabilize G-quadruplex over duplex DNA, and also to discriminate among different G-quadruplex structures, having a part...
Our previous total synthesis of the proposed structures of jiangrines C and D shows that the characteristic data of synthetic samples did not match those of the natural ones, prompting us to revise their structures. Accordingly, we now accomplished the total synthesis of jiangrines A, C and D, which confirms our deduction that their molecular skeletons should compose of 2,3-disubstituted pyrrol...
Enecarbamates are shown to be excellent terminating groups for Prins cyclizations. A noteworthy feature of this methodology is the easy, stereoselective construction of the cyclization precursors by alkylation of metalated (E)-enecarbamates with epoxides. The stereochemistry of the resultant trisubstituted (E)-enecarbamates is then transferred with high fidelity to afford the frequently observe...
A convenient microwave irradiation protocol was utilized for the synthesis of b-ketosulfones 1-5 in good yields. These sulfones reacted with alkenes through a radical oxidative cyclization mediated by Mn(OAc)3. Dihydrofurans 6-10 were obtained in moderate to good yields starting from 1,1-disubstituted alkenes. Dihydrofurans 11-15 were synthesized in moderate yields and unexpected cyclopropanes ...
the synthesis of some 9,10-disubstituted anthracene derivatives are described. 9,10-bis(2-bromoethyl) anthracene 4,9,10-bis (2-cyanoethyl) anthracene 5 and 9,10-bis (4-hydroxybutyl) anthracene 11 are synthesized for the first time.
In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted-1,2,3-triazoles 4a-l by employing the (3+2) cycloaddition reaction of pyrimidinones containing alkyne functions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-...
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