Реакция #56025

Уравнение реакции

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

Растворители

water

Условия реакции

Обработка

1. 1
   ДругоеApproximately 15 minutes
2. 2
   workup.ADDITIONis slowly introduced, whereupon the reaction mixture
3. 3
   Температураis heated at 55° for 3 hours
4. 4
   workup.STIRRINGstirring
5. 5
   Температураthe nitrogen atmosphere maintained throughout
6. 6
   ФильтрацияInsoluble solids are filtered out
7. 7
   Другоеcrystallized from aqueous N,N-dimethylformamide

Методика

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°.

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