Yield: 92%

Reaction Conditions:

with hydrogen;palladium on activated charcoal in tetrahydrofuran at 35; for 4 h;

Steps:

27 Synthesis of 8-amino-6-chloro-2H-benzo[b][1,4]oxazin-3(4H)-one
Synthesis of 8-amino-6-chloro-2H-benzo[b][1,4]oxazin-3(4H)-one A 1000 mL 3-necked round-bottom flask was purged, flushed and maintained with a hydrogen atmosphere, then, was added a solution of 6-chloro-8-nitro-2H-benzo[b][1,4]oxazin-3(4H)-one (8 g, 35.00 mmol, 1.00 equiv) in THF (700 mL). To the mixture was added Pd/C (3 g). The resulting solution was allowed to react, with stirring, for 4 h while the temperature was maintained at 35° C. in a bath of oil. The reaction progress was monitored by TLC (EtOAc/PE=1:1). A filtration was performed. The filtrate was concentrated by evaporation under vacuum using a rotary evaporator. This resulted in 6.7 g (92%) of 8-amino-6-chloro-2H-benzo[b][1,4]oxazin-3(4H)-one as a brown solid.

References:

MEMORY PHARMACEUTICALS CORPORATION US2008/318941, 2008, A1 Location in patent:Page/Page column 42-43