Dihydro-2//-1,4-benzoxazines

Benzoxazinones pyrolysis, 3, 998 Benzoxazinones, dihydro-benzazetidine formation from, 7, 277 Benzoxazin-4-ones, dihydrosynthesis, 3, 1028... 

Imidazolinyl) derivative of 8-methyl-2,3,6,7-tetrahydro-5 f- and 8-methyl-7-methoxy-5-oxo-2,3-dihydro-5 f-pyrido[l, 2, i-de]-1,4-benzoxazines were included in a 3D-QSAR CoMFA study on imidazolinergic I2 ligands (00JMC1109). 

An on-line chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI/MS/MS) methods was developed for rapid screen of pharmacokinetics of different drugs, including 5 (98RCM1216). The electron impact mass spectrum of 5 and ethyl 9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7Ff-pyrido[l,2,3- fe]-l,4-benzoxazine-6-carboxylate was reported (97MI28). Electron impact/Fourier transform... 

The solid state structure of (3>S,8 Sj-10-(8-amino-6-azaspiro[3,4]octan-6-yl)-9-fluoro-3-methyl-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-dfe]-l,4-benzoxa-zine-6-carboxylic acid (218) was determined by X-ray diffraction study (98CPB1710). The structure of 6,10-dihydropyrido[2,l-c][l,4]benzoxazine-6,10-dione 219 was established by X-ray diffraction analysis. It contains a crystal solvate with /j-xylene (99MI40). 

Reaction of 2,3-dihydro-3-hydroxy-3-methyl- 240 (R = Me), or a mixture of 2,3-dihydro-3-hydroxy-3-aryl-57/-pyrido[l,2,3-dfe]-l,4-benzoxazin-5-ones 240 (R = Ar) and (8-aroylmethoxy)quinolin-2(l//)-ones 241 (R = Ar) with ethyl 2-(bromomethyl)acrylate in the presence of activated Zn and hydroquinone gave 8-[(2,3,4,5-tetrahydro-4-methylidene-5-oxo-2-furanyl)-methoxy]quinolin-2(l//)-ones (242) (97HCA1161). 6,7-Dihydro derivatives of 240 reacted similarly (00HCA349). 

Treatment of ethyl 10-methylthio-9-fluoro-3-methyl-2,3-dihydro-7-oxo-7//-pyrido[l,2,3- 7e]-l,4-benzoxazine-6-carboxylate with oxone in aqueous MeOH at 0°C afforded 10-methylsulfonyl derivative (99H(51)1563). Methylthio group in a 7-(4-methylthiophenyl)-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- 7e]-l,4-benzoxazine-3-carboxamide was oxidized to a sulfoxide and a sulfone group (OOMIPl). 

Reaction of 9,10-difluoro-3-methyl-2,3-dihydro-7-oxo-7//-pyrido[l,2,3- /e]-l,4-benzoxazine-6-carboxylic acid (252 X = F, R = H, R = Me) with 8 M aquous solution of KOH under reflux for 6 h, and in the presence of an alcohol or phenol afforded 10-hydroxy, 10-alkoxy and 10-aryloxy derivatives, respectively (96JAP(K)96/291144, 99MI5). 

Reaction of iV-(4-chlorobenzyl)-9-iodo-7-oxo-2,3-dihydro-7//-pyrido [l,2,3- /e]-l,4-benzoxazine-6-carboxamide and HC=CCH20H in the presence of Cu(I)I and (PPh3)2PdCl2 in Et2NH under argon atmosphere for 18h gave 9-(3-hydroxy-l-propynyl) derivative (01MIP2). 

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