反応 #570050

反応方程式

3-carbomethoxy-4-carbethoxy-1-oxo-pyrido[2,1-C][1,4]benzothiazine

HCl

→

product

収率 74.0%

1-Oxo-pyrido[2,1-C][1.4]benzothiazine-3,4-dicarboxylic acid

収率 74.0%

溶媒

NaOH

ethanol

反応条件

後処理

1. 1
   ろ過filtered
2. 2
   洗浄the precipitate washed with water
3. 3
   その他dried
4. 4
   その他to give 8.5 g crude solid which
5. 5
   その他was purified
6. 6
   workup.DISSOLUTIONby dissolving in IN NaOH
7. 7
   その他crystallizing out by addition of IN HCl
8. 8
   ろ過It was then filtered
9. 9
   洗浄washed with water and ether

実験手順

A mixture of 12 g of 3-carbomethoxy-4-carbethoxy-1-oxo-pyrido[2,1-C][1,4]benzothiazine in 270 ml 0.5N NaOH and 60 ml ethanol was stirred at 60° C. for 2 hrs. It was then acidified with 1N HCl, filtered, the precipitate washed with water and dried to give 8.5 g crude solid which was purified by dissolving in IN NaOH, and crystallizing out by addition of IN HCl. It was then filtered, washed with water and ether to give 7.8 g product, m.p. 222° C. (decomposition).

出典