نتایج جستجو برای: benzoxazin
تعداد نتایج: 252 فیلتر نتایج به سال:
Gas-liquid chromatography-mass spectrometry (GLC-MS) has been used for the separation, detection, and identification of 1,4-benzoxazin-3-ones (hydroxamic acids and lactams) and benzoxazolinones found in maize (Zea mays L.) extracts. Compounds of interest were partitioned into ethyl acetate from aqueous maize seedling extracts. For analysis by GLC-MS, trimethylsilyl derivatives were prepared, ch...
Contents of three 1,4-benzoxazin-3-ones in tissue samples from different parts (young leaf, second leaf, old leaf, stem and root) of young maize plants of 4-leaves stage, fed by the third instar larvae of the Asian corn borer, Ostrinia furnacalis (Guenée), were analyzed by high-performance liquid chromatography-mass spectroscopy (HPLC-MS). Samples were taken immediately (set A) or 48 h (set B) ...
A gas-liquid chromatographic (GLC) procedure is reported for the quantitation of the trimethylsilyl (TMS) derivatives of substituted 2-hydroxy-2H-1,4-benzoxazin-3(4H)-ones (2-hydroxy-2H-1,4-benzoxazin-3(4H)-one[HBOA]; 2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one[HMBOA];2,4- dihydroxy-2H-1,4-benzoxazin-3(4H)-one[DIBOA]; 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one[DIMBOA]; and 2,4-dihy...
BACKGROUND The derivatives of 2-substituted 4H-3,1-benzoxazin-4-one belong to a significant category of heterocyclic compounds, which have shown a wide spectrum of medical and industrial applications. RESULTS A new and effective one-pot method for the synthesis of 2-substituted 4H-3,1-benzoxazin-4-one derivatives is described in this paper. By using the iminium cation from a mixture of cyanur...
A novel and efficient one-pot cascade synthesis of 2H-1,4-benzoxazin-3-(4H)-ones has been developed through copper-catalyzed coupling of o-halophenols and 2-halo-amides. Various 2H-1,4-benzoxazin-3-(4H)-ones with diversity at three substituents on their scaffold have been synthesized conveniently in good to excellent yields.
The most valuable organs of plants are often particularly rich in essential elements, but also very well defended. This creates a dilemma for herbivores that need to maximise energy intake while minimising intoxication. We investigated how the specialist root herbivore Diabrotica virgifera solves this conundrum when feeding on wild and cultivated maize plants. We found that crown roots of maize...
Benzoxazinones 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA) and 2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA) have been considered key compounds for understanding allelopathic phenomena in Gramineae crop plants such as corn (Zea mays L.), wheat (Triticum aestivum L.), and rye (Secale cereale L.). The degradation processes in the environment observed for these compounds, ...
A synthesis of the originally proposed 2-(1 H-indol-3-yl)-4 H-3,1-benzoxazin-4-one structure of the alkaloid cephalandole A (1) led to a structural revision, and the isolated natural product has now been identified as the previously known compound 3-(1 H-indol-3-yl)-2 H-1,4-benzoxazin-2-one (7). The structural assignment was corroborated by detailed NMR studies. A short synthesis of the related...
A new phenylethanoid glycoside acylated with syringic acid, namely acanmontanoside, was isolated from the aerial portions of Acanthus montanus (Nees). T. Anderson, along with decaffeoylverbascoside, verbascoside, isoverbascoside, leucosceptoside A, (2R)-2-O-ß-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (HBOA-Glc), (2R)-2-O-ß-D-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA-Glc), (...
An efficient synthesis of 3-substituted or 2,3-disubstituted 4(3H)-quinazolinones from benzoxazin-4-ones and primary amines under microwave irradiation in unsealed vessels is described.
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