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6358-08-3
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79-04-9 Synthesis

79-04-9
366 suppliers
$12.00/5g

6-CHLORO-8-NITRO-4H-BENZO[1,4]OXAZIN-3-ONE

870064-73-6
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$85.00/100mg

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Yield:870064-73-6 72%

Reaction Conditions:

with N-benzyl-N,N,N-triethylammonium chloride;potassium carbonate in chloroform at 0 - 55;

Steps:

27 Synthesis of 6-chloro-8-nitro-2H-benzo[b][1.4]oxazin-3 (4H)-one

Example 27 Preparation of 3-Oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-8-sulfonyl Chloride Synthesis of 6-chloro-8-nitro-2H-benzo[b][1.4]oxazin-3 (4H)-one Into a 5000 mL 3-necked round-bottom flask, was placed a solution of 2-amino-4-chloro-6-nitrophenol (40 g, 212.09 mmol, 1.00 equiv) in CHCl₃ (2500 mL). To this was added N-benzyl-N-chloro-N,N-diethylethanamine (TEBA, 48 g, 210.53 mmol, 1.00 equiv). To the mixture was added K₂CO₃ (88 g, 637.68 mmol, 3.00 equiv). This was followed by the addition of a solution of 2-chloroacetyl chloride (28.8 g, 254.87 mmol, 1.20 equiv) in CHCl₃ (500 mL), which was added dropwise with stirring, while cooling to a temperature of 0-5° C. The resulting solution was allowed to react, with stirring, for 1 h while the temperature was maintained at 0-5° C. in a bath of ice/salt. The reaction progress was monitored by TLC (EtOAc/PE=1:5). The resulting solution was allowed to react, with stirring, overnight while the temperature was maintained at 55° C. in a bath of oil. The reaction progress was monitored by TLC (EtOAc/PE=1:5). A filtration was performed. The filtrate was concentrated by evaporation under vacuum using a rotary evaporator. The resulting solution was diluted with 500 mL of H₂O. A filtration was performed. The final product was purified by recrystallization from EtOH. This resulted in 34.7 g (72%) of 6-chloro-8-nitro-2H-benzo[b][1,4]oxazin-3(4R)-one as a brown solid.

References:

US2008/318941,2008,A1 Location in patent:Page/Page column 42

6358-08-3
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105-36-2 Synthesis