Highly efficient approach to the total synthesis of flavoxate hydrochloride

An efficient and short approach to the total synthesis of flavoxate hydrochloride, a muscle relaxant in urinary bladder, is reported. The synthesis of flavoxate hydrochloride is accomplished from o-cresol in 5 steps with 60.3% overall yield using formylation with formaldehyde, Grignard reaction with ethylmagnesium bromide, oxidation with potassium permanganate, Kostanecki-Rabinson cyclization and esterification with thionyl chloride and piperidinoethanol as linear steps. [Display omitted]