37522-26-2Relevant articles and documents
3-Substituted Benzo[ e][1,2,4]triazines: Synthesis and Electronic Effects of the C(3) Substituent
Bodzioch, Agnieszka,Pomik?o, Dominika,Celeda, Ma?gorzata,Pietrzak, Anna,Kaszyński, Piotr
, p. 6377 - 6394 (2019/05/24)
A series of 19 structurally diverse C(3)-substituted derivatives of benzo[e][1,2,4]triazine were synthesized from 3-chloro- (1c) and 3-iodobenzo[e][1,2,4]triazine (1d) obtained in three steps from 2-nitroaniline in 37-55% yields. Nucleophilic aromatic substitution and metal-catalyzed (Pd, Cu) reactions led to functional derivatives that include alkyl (C5H11), (het)aryl (Ph, 2-thienyl, ferrocenyl), ArCC, amine (NHPh and morpholine), PO(OEt)2, sulfanyl (SBu-t), alkoxide (OEt, OMe), and CN. The synthesis of C(3)-CF3 derivative 1g via the Ruppert reaction with 1d and its 1-oxide analogue 2d led to the substitution followed by formal addition of HCF3 to the C?N bond. Pd-catalyzed carbonylation reactions of 1d and 2d did not give the corresponding C(3)-carboxylic acids. Therefore, acid 1f was obtained through hydrolysis of the CN. The substituent effect on the electronic structure of the benzo[e][1,2,4]triazine ring was investigated by spectroscopic methods (UV-vis and NMR) augmented with density functional theory calculations. Results show significant effect of the C(3) substituent on the (1) transition energy and good correlation of the 1H NMR chemical shift with the substituent constant σp. Molecular and crystal structures of six derivatives were established with the single-crystal X-ray diffraction method, and the substituent impact on the molecular geometry was investigated.
Phytotoxic activity in pyrazole derivatives. I
Bernard,Cocco,Maccioni,Plumitallo
, p. 259 - 271 (2007/10/02)
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