NEW 1,4-BENZOTHIADINE DERIVATIVE

PROBLEM TO BE SOLVED: To obtain a new 1,4-benzothiadine derivative useful for pharmaceutical and agrochemical obtained by the Pinner type cyclization using acid-alcohol solution. SOLUTION: These compounds are 1,4-benzothiadine derivatives of formula I (R is a 1-6C chain or a cyclic alkyl) or tautomers of 1,4-benzothiadine derivatives of formula II and III, for example, tautomers of 3-amino-2-methoxy-2 H-1,4-benzothiamidine and thiamidine 1,4-dioxide. The compound of formula I is obtained by acting an oxidizing agent on the sulfide of the compound of formula IV giving a sulfoxide then carrying out the Pinner type cyclization using an acid-alcohol solution. The tautomers of formula II and III are obtained by acting oxidizing agent on the sulfide of the compound of formula IV giving a sulfoxide then carrying out the Pinner type cyclization using an acid-alcohol solution.