7484-41-5Relevant academic research and scientific papers
Stereoselective synthesis of dihydrothiadiazinoazines and dihydrothiadiazinoazoles and their pyrolytic desulfurization ring contraction
Al-Etaibi, Alya,John, Elizabeth,Ibrahim, Maher R.,Al-Awadi, Nouria A.,Ibrahim, Yehia A.
experimental part, p. 6259 - 6274 (2011/09/19)
Intramolecular base catalyzed C-C bond formation led to exclusive stereoselective syntheses of trans-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4] thiadiazines, trans-7,8-dihydro-6H-[1,2,4]triazino[3,4-b][1,3,4]thiadiazin-4- ones, and trans-3,4-dihydro-2H-
Efficient dual catalytic enantioselective diethylzinc addition to the exocyclic C{double bond, long}N double bond of some 1,2,4-N-triazinylarylimines using polymer-supported chiral β-amino alcohols derived from norephedrine
El-Shehawy, Ashraf A.
, p. 5490 - 5500 (2008/01/07)
Chiral N,N-dialkylnorephedrines and their corresponding copolymers were evaluated as chiral ligands for the enantioselective diethylzinc addition to the exocyclic C{double bond, long}N double bond of some 4-arylideneamino-3-mercapto-6-methyl-4H-1,2,4-triazin-5-ones 2a-f. The use of a dual catalytic system (amino alcohol/halosilane) in the titled asymmetric reaction was examined. The enantioselective ethylation reaction has been successfully carried out in the heterogeneous system even at low temperature. The corresponding 4-(1-arylpropyl)amino-3-mercapto-6-methyl-4H-1,2,4-triazin-5-ones 4a-f were obtained in high yields with high enantioselectivities using chiral polymers (up to 91% ee), which are almost the same as those obtained from homogeneous analogues (up to 92% ee). The diethylzinc reagent neither opened the 1,2,4-triazinyl heterocyclic ring nor attacked the carbonyl or the thione groups of the 1,2,4-triazinyl heterocyclic ring and the addition reaction took place exclusively at the exocyclic electrophilic carbon atom yielding the C-ethylated products 4a-f. Reductive cleavage of the 1,2,4-triazinyl heterocyclic ring led smoothly to the corresponding primary aromatic amines 11a-f without significant loss of enantiomeric purity. A?suggestion about the possible transition state for the addition reaction is also presented.
Enantioselective diethylzinc addition to the exocyclic C{double bond, long}N double bond of some 4-arylideneamino-3-mercapto-6-methyl-4H-1,2,4-triazin-5-one derivatives
El-Shehawy, Ashraf A.
, p. 2617 - 2624 (2007/10/03)
4-Arylideneamino-3-mercapto-6-methyl-4H-1,2,4-triazin-5-ones 2a-f have been evaluated as substrates in the enantioselective diethylzinc addition reaction in the presence of (1S,2R)-N-alkyl-N-benzylnorephedrines 3a-d as chiral ligands. The utility of using a dual catalytic system (amino alcohol/halosilane) for the diethylzinc addition reaction has been also examined. The addition products 4-(1-arylpropyl)amino-3-mercapto-6-methyl-4H-1,2,4-triazin-5-ones 4a-f were obtained in high yields and with enantiomeric excesses of up to 92%. The treatment of arylimines 2a-f with a diethylzinc reagent did not affect the hetero-ring opening although the C{double bond, long}N double bond of the lateral chain did undergo an addition reaction to yield the C-ethylated products 4a-f. The reductive cleavage of the 1,2,4-triazinyl heterocyclic ring from addition products 4a-f led smoothly to the corresponding free primary amines 5a-f without a significant loss of enantiomeric purity.
New synthesis of [1,3,4] thiadiazolo [2,3-c][1,2,4] triazinone; transfer of active electron by microwaves
Abdi Oskooie,Heravi,Khosrofar,Faridbod
, p. 2399 - 2402 (2007/10/03)
Reaction of various aromatic aldehydes with 4-amino-6-methyl-1,2,4-triazin-5-one supported on to montmorillonite-K10 in the presence of nitrobenzene under microwaves irradiation, afforded the corresponding [1,3,4] thiadiazole [2,3-c][1,2,4]-triazinones.
Synthesis and Structure of as-Triazinoquinazolines, II.
Badawy, Mohamed A.,Abdel-Hady, Sayed A. L.,Eid, Mohga M.,Ibrahim, Yehia A.
, p. 1083 - 1088 (2007/10/02)
4-Amino-3-(methylthio)-6-R-1,2,4-triazin-5(4H)-ones 6-10 react with anthranilic acid to yield the 1-amino-3-R-2H-as-triazinoquinazoline-2,6(1H)-diones 17-21 rather than the expected as-triazinobenzotriazepines 12-16.Compounds 17-21 were deaminated into compounds 22-26.Heating of the N-benzylidene derivatives of 6-10 (27-31) with anthranilic acid also led to the formation of 22-26 with extrusion of benzonitrile.
