Diethyl bromomalonate (2) with an equimolar amount of 2-aminophenol (1) in the presence of sodium fluoride undergoes a cyclization reaction to form 2H,4H-2-ethoxycarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (3). Furthermore, compound 3 undergoes a condensation reaction with hydrazine hydrate in the presence of methanol to yield 2H,4H-2-hydrazinocarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (4), whic...

The synthetic access to 2-sec-amino-4H-3,1-benzothiazin-4-ones 2 was explored. Compounds 2 were available from methyl 2-thioureidobenzoates 1, 2thioureidobenzoic acids 3, and novel 2-thioureidobenzamides 6, respectively, under different conditions. 2-Alkylthio-4H-3,1-benzothiazin-4-ones 5 have been prepared from anthranilic acid following a two step route. Both, benzothiazinones 2 and 5 underwe...

The synthetic access to 2-sec-amino-4H-3,1-benzothiazin-4-ones 2 was explored. Compounds 2 were available from methyl 2-thioureidobenzoates 1, 2-thioureidobenzoic acids 3, and novel 2-thioureidobenzamides 6, respectively, under different conditions. 2-Alkylthio-4H-3,1-benzothiazin-4-ones 5 have been prepared from anthranilic acid following a two step route. Both, benzothiazinones 2 and 5 underw...

Diazotization of 3-amino-2-cMoro pyridine (3) in the presence of dithizone (5) gave dphenyl-2-phenylazo-4H-pyrid[o3 ,2-e] [1,3,4] thiadiazine (6). Reaction of 2- chloro-3-nitropyridine (2, G=H) with (5) dfordd 4-phenyl -2-phenylazo -4Hpyrido [2,3-el [1,3,4] thiadiazine (7). Reduction of the latter with H gas in the presence of Raney nickel gave the corresponding amino derivative (12). One ...