反応 #56025

反応方程式

7-chloro-3-methylthio-2H-1,4-benzothiazine

acetic acid

sodium hydride

N,N-dimethylformamide

2-cyanoacetamide

→

2-cyano-2-(7-chloro-2,3-dihydro-4H-benzothiazin-3-ylidene)acetamide

溶媒

water

反応条件

後処理

1. 1
   その他Approximately 15 minutes
2. 2
   workup.ADDITIONis slowly introduced, whereupon the reaction mixture
3. 3
   温度is heated at 55° for 3 hours
4. 4
   workup.STIRRINGstirring
5. 5
   温度the nitrogen atmosphere maintained throughout
6. 6
   ろ過Insoluble solids are filtered out
7. 7
   その他crystallized from aqueous N,N-dimethylformamide

実験手順

To approximately 23 parts of sodium hydride in 4800 parts of N,N-dimethylformamide at room temperature under nitrogen is added, portionwise with stirring, 78 parts of 2-cyanoacetamide. Approximately 15 minutes later, a solution of 7-chloro-3-methylthio-2H-1,4-benzothiazine preparable as described in Part B of this example is slowly introduced, whereupon the reaction mixture is heated at 55° for 3 hours and then allowed to cool to room temperature overnight, stirring being continuous and the nitrogen atmosphere maintained throughout. The resultant mixture is acidified with glacial acetic acid and thereupon mixed with 3 volumes of water. Insoluble solids are filtered out and crystallized from aqueous N,N-dimethylformamide to give 2-cyano-2-(7-chloro-2,3-dihydro-4H-benzothiazin-3-ylidene)acetamide melting with decomposition in the range 150°-160°.

出典