Method of producing 1, 2, 4-benzothiadiazine-1, 1-dioxide compound

摘要

A method of producing 1,2,4-benzothiadiazine-1,1-dioxide compound of formula (I), including reacting a 2-aminobenzenesulfonamide compound with a 1,1-dialkoxyalkene compound or with an orthoester compound, in the presence of an acid, to obtain an iminoether compound, and then subjecting the iminoether compound to a ring closure reaction, in the presence of a base: <CHEM> wherein, in formula (I), R1 is an alkyl group, or an aryl group; R2 is a substituent; n is 0 to 4; and R3 is a hydrogen atom or a substituent.