In the chemical reaction process,reaction time,type of solvent,can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product.An updated downstream synthesis route of 188614-01-9,Methyl 3-oxo-3,4-dihydro-2H-1,4-benzothiazine-6-carboxylate, as follows.188614-01-9
A. 3-Oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid. To a solution of 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxylic acid methyl ester (1.5 g, 6,7 mmol) in a THF/H2O mixture (1:1, 63 mL) was added 4 N LiOH (8.0 mL, 32 mmol) and the resulting solution was stirred at RT for 24 h. The solution was partially concentrated and diluted with H2O (50 mL). The solution was acidified using concentrated HCl and a solid precipitated. The solid was collected via filtration, washed with H2O and dried in vacuo to provide 0.79 g (60%) of the title compound as a white solid. MS (ESI): exact mass calculated for C9H7NO3S, 209.01; m/z found, 210.2 [M+H]+. 1H NMR (500 MHz, CD3OD): 7.65-7.61 (m, 2H), 7.40 (d, J=8.1, 1H), 3.48 (s, 2H).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 188614-01-9, and friends who are interested can also refer to it.
Reference£º
Patent; Allison, Brett D.; Gomez, Laurent; Grice, Cheryl A.; Hack, Michael D.; Morrow, Brian J.; Motley, S. Timothy; Santillan, Alejandro; Shaw, Karen J.; Schwarz, Kimberly L.; Tang, Liu Y.; Venkatesan, Hariharan; Wiener, John J. M.; US2006/223810; (2006); A1;,
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