| 摘要 |
<p>The invention aims at providing crystals of 6-fluoro-1 -methyl-7- [4-(5-methyl -2-oxo- 1, 3-dioxolen- 4-yl)- methyl-1-piperazinyl] -4-oxo-4H -[1, 3] thiazeto [3, 2-a]quino- line-3- carboxylic acid acetonitrile solvate (compound B) which are useful as an intermediate for producing preferentially III-type crystals of 6-fluoro- 1-methyl-7- [4-(5-methyl- 2-oxo -1, 3-dioxolen- 4-yl) methyl-1-piperazinyl] -4-oxo-4H -[1,3]- Thiazeto [3,2-a] quinoline -3-carboxylic acid (compound A). Compound B can be preferentially crystallized from acetonitrile by controlling the supersaturation concentration, and desolvation of the crystals of compound B can give III-type crystals of compound A.</p> |
