Displacement of the chloride group of 4-chloro-3-nitrobenzoic acid (I) with sodium disulfide, followed by reduction of the disulfide and nitro groups with Sn/HCl yields 3-amino-4-mercaptobenzoic acid (II), which is further esterified to (III) with methanolic HCl. Condensation of (III) with 2,3-dichloropyrazine (IV) produces the pyrazinobenzothiazine compound (V). The ester group of (V) is then reduced to alcohol (VI) employing LiAlH4. Subsequent treatment of alcohol (VI) with methanesulfonyl chloride and pyridine leads to the benzyl chloride (VII).

4-Amino-1-benzylpiperidine (VIII) is condensed with dimethylsulfamoyl chloride to give the sulfamide (IX). Subsequent benzyl group hydrogenolysis in (IX) over Pd/C provides the piperidine (X). Finally, alkylation of piperidine (X) with chloride (VII) yields the title compound.

Displacement of the chloride group of 4-chloro-3-nitrobenzoic acid (I) with sodium disulfide, followed by reduction of the disulfide and nitro groups with Sn/HCl yields 3-amino-4-mercaptobenzoic acid (II), which is further esterified to (III) with methanolic HCl. Condensation of (III) with 2,3-dichloropyrazine (IV) produces the pyrazinobenzothiazine compound (V). The ester group of (V) is then reduced to alcohol (VI) employing LiAlH4. Subsequent treatment of alcohol (VI) with methanesulfonyl chloride and pyridine leads to the benzyl chloride (VII).

4-Amino-1-benzylpiperidine (VIII) is condensed with dimethylsulfamoyl chloride to give the sulfamide (IX). Subsequent benzyl group hydrogenolysis in (IX) over Pd/C provides the piperidine (X). Finally, alkylation of piperidine (X) with chloride (VII) yields the title compound.