Saccharin (II) was obtained by acidification of a solution of sodium 2-sulfamoylbenzoate (I). Alkylation of the sulfimide N of (II) with N-(2-pyridyl)bromoacetamide (III) under phase-transfer conditions afforded (IV). Rearrangement of sulfimide (IV) in the presence of sodium methoxide gave rise to the benzothiazine derivative (V). From this, the title compound was prepared by two related ways. Esterification of (V) with trimethylacetyl chloride yielded pivalate ester (VI), which was subsequently alkylated at the sulfamide N with iodomethane in the presence of NaOH. Alternatively, methylation of (V), followed by esterification of the resultant (VII) with pivaloyl chloride led to the title compound.