1.5.6.7- Tetrahydro-3//-pyrido 3.1 benzothiazin-3-ones

Mixtures of l-(3-chloropropyl)-l,4-dihydro-2//-[3,l]benzothiazin-2-ones or their 3,3-dioxides and anhydrous AICI3 were stirred at ambient temperature for 30 min, and then at 170-180°C for 1 h, to give 1,5,6,7-tetrahydro-3i/-pyrido[3,2,l- ][3,l]benzothiazin-3-ones and their 2,2-dioxides [88JAP(K)88/170385]. 

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