These common heterocyclic compound, 89976-75-0, name is 6-Amino-2H-1,4-benzoxazin-3(4H)-one, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. COA of Formula: C8H8N2O2
B. To a solution of 1-phenyl-piperidine-4-carboxylic acid (0.03 g, 0.122 mmol) in 5 mL of CH2Cl2 was added oxalyl chloride (0.02 mL, 0.244 mmol) and a catalytic amount of DMF. The reaction mixture was stirred for 2 hours. Solvent was evaporated to dryness under reduced pressure. The residue was redissolved in 5 mL of CH2Cl2. 6-amino-2H-1,4-benzoxazine-3(4H)-one (0.02 g, 0.122 mmol) and triethylamine (0.03 mL, 0.183 mmol) were added sequentially into the acyl chloride solution at 0¡ã C. The reaction mixture was warmed to 25¡ã C. and stirred for 20 min. Concentration of the solvent provided the residue which was then purified by flash column chromatography with hexanes and ethyl acetate to afford 1-phenyl-piperidine-4-carboxylic acid (3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-6-yl)-amide as white solid. 1H NMR (400 MHz, CD3OD) delta (ppm): 7.61-7.58 (m, 4H), 7.54-7.51 (m, 1H), 7.39 (t, 1H), 7.04-7.01 (m, 1H), 6.91 (d, 1H), 4.54 (s, 2H), 3.84 (d, 2H), 3.66-3.59 (m, 2H), 2.82-2.79 (m, 1H), 2.28-2.23 (m, 4H). Mass Spectrum (LCMS, ESI pos.) Calcd. for C20H21N3O3: 351.4. Found: 352.1 (M++1).
The synthetic route of 6-Amino-2H-1,4-benzoxazin-3(4H)-one has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Calvo, Raul R.; Cheung, Wing S.; Player, Mark R.; US2006/116368; (2006); A1;,
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