Alkylation of 3-hydroxybenzyl alcohol (II) with 2-chloromethylquinazoline (I) in the presence of K2CO3 and tetrabutylammonium bromide provided ether (III). The hydroxyl group of (III) was converted to chloride (IV) by treatment with thionyl chloride. Finally, alkylation of hydroxybenzothiazinone (V) with chloride (IV) yielded the title compound.

Alkylation of 3-hydroxybenzyl alcohol (II) with benzimidazolylmethyl chloride (I) in the presence of K2CO3 and tetrabutylammonium bromide provided ether (III). The hydroxyl group of (III) was converted to chloride (IV) by treatment with thionyl chloride. Finally, alkylation of hydroxybenzothiazinone (V) with chloride (IV) yielded the title compound.

Alkylation of 3-hydroxybenzyl alcohol (II) with 2-chloromethylquinazoline (I) in the presence of K2CO3 and tetrabutylammonium bromide provided ether (III). The hydroxyl group of (III) was converted to chloride (IV) by treatment with thionyl chloride. Finally, alkylation of hydroxybenzothiazinone (V) with chloride (IV) yielded the title compound.

Alkylation of 3-hydroxybenzyl alcohol (II) with benzimidazolylmethyl chloride (I) in the presence of K2CO3 and tetrabutylammonium bromide provided ether (III). The hydroxyl group of (III) was converted to chloride (IV) by treatment with thionyl chloride. Finally, alkylation of hydroxybenzothiazinone (V) with chloride (IV) yielded the title compound.