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...

The NHC-catalyzed reactions of ortho electron-deficient vinyl substituted arylaldehydes with nitrosoarenes were studied. The reactions produced multifunctional 2,3-benzoxazin-4-ones in good to excellent yields via a cascade aza-benzoin reaction between aldehyde and nitroso groups followed by an intramolecular oxo-Michael addition. The resulting 1-acetate substituted 2,3-benzoxazinones were tran...

2-[2-(2,6-Dichlorophenyl)amino]phenylmethyl-3-{4-[(substituted phenyl)amino]-1,3-oxazol-2-yl)-7-chloroquinazolin-4(3H)ones 5a-o have been prepared from 2-[(2,6-dichloro phenyl)amino]phenyl acetic acid 1, which was converted to acid chloride 2 and cyclized with anthranilic acid afforded benzoxazin-4(H)ones 3. Further reaction with urea gave carboxamide-7-chloroquinazolin-4(3H)ones 4 cyclized wit...

The solid-phase synthesis of 4H-3,1-benzoxazin-4-ones was achieved using silica-bound benzoyl chloride (SBBC) as dehydrating agent in reaction with 2-acylaminobenzoic acids. The silica-grafted reagent (SBBC) was simply recovered after reaction and reused several times.

Treating 2-chloro-4-(4-chlorophenyl)-6-methylbenzo[d]-3,1-oxazinium hexachloroantimonate (1) with one equivalent of alcohol or mercaptane led, after hydrolysis with aq. NaOH, to the formation of 4,4-disubstituted-1,4-dihydro-2H-6-methyl-3,1-benzoxazin-2-ones (3). Large excess addition of alcohol afforded either 4’-chloro-2-isocyanato-5-methylbenzophenone disubstitutedketal (4) or N-{2[(4-chloro...

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...