2- [2 - ((s) -3-dimethylaminopyrolidin-1-yl) pyridin-3-yl] -5-ethyl-7-methoxy-4h-benz [d] [1,3] oxazine maleic acid salt -4-one； 2- [2 - ((s) -3-dimethylaminopyrolidin-1-yl) pyridin-3-yl)] -5-ethyl-7-methoxy-4h-benz [d] [1,3] oxazine-4 crystals -one； maleate and monomaleate； mixtures of these crystals, methods for the production and recrystallization of 2- [2 - ((s) -3-dimethylaminopyrolidin-1-yl) pyridin-3-yl)] -5-ethyl-7-methoxy-4h-benz crystal [d] [1,3] oxazine-4-one； monomaleate and medicine containing this crystal
Disclosed is a benz[d][1,3]oxazine derivative having excellent stability when used as an active ingredient for a medicinal agent, and also having excellent solubility and crystallinity. Specifically disclosed is 2-[2-((S)-3-dimethylaminopyrrolidin-1-yl)pyridin-3-yl]-5-ethyl-7-methoxy-4H-benz [d][1,3]oxazin-4-one maleate.
