نتایج جستجو برای: benzoxazines
تعداد نتایج: 156 فیلتر نتایج به سال:
A series of new 2,3-disubstituted-3,4-dihydro-2H-1,3-benzoxazines were prepared in moderate to excellent yields by aza-acetalizations of aromatic aldehydes with 2-(N-substituted aminomethyl)phenols in the presence of TMSCl. Their structures were confirmed by IR, ¹H-NMR, ¹³C-NMR, MS and elemental analysis. The fungicidal activities of the target compounds were preliminarily evaluated, and some c...
A new series of N,N'-bis(2'-hydroxy-5'-substituted-benzyl)-N,N -dimethylethane-1,2-diamines (N,N'-dimethyltetrahydrosalen) ligands were prepared in good yield by reduction of the respective 3,3'-ethylene-bis(3,4-dihydro-6-substituted-2H-1,3-benzoxazine) precursors with sodium borohydride . The ligands were characterized by IR, NMR, and elemental analysis, which showed the compounds to be consis...
The title benzoxazine molecule, C18H18Br2N2O2, was prepared by a Mannich-type reaction of 4-bromo-phenol with ethane-1,2-di-amine and formaldehyde. The title compound crystallizes in the monoclinic space group C2/c with a centre of inversion located at the mid-point of the C-C bond of the central CH2CH2 spacer. The oxazinic ring adopts a half-chair conformation. The structure is compared to tho...
Four previously synthesized (R =-F,-F,-CI,-Br,-l) and one new (R=-H) 3,3' -ethylene-bis(3,4-dihydro-6R-2H-1,3-benzoxa2Íne) were preliminary tested for insecticidal activity against M. domestica (Díptera) and C. cary (Lepidoptera) larvae. Under laboratory conditions no toxic action was observed. All larvae continued development and pupated successfully but internal or external malformations were...
A highly efficient enantioselective aryl addition to aldehydes using boroxins as aryl source and conformationally restricted perhydro-1,3-benzoxazines as ligands is reported. Both enantiomeric forms of chiral arylphenylmethanols and 1,1'-disubstituted diarylmethanols are afforded with excellent yields and enantioselectivities using the same ligand by means of an appropriate combination of borox...
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