p-Toluenesulfonic acid monohydrate → HCID 86604793, compound

Participants

Reaction Conditions

Reaction Steps

4-[2,2,4-Trioxo-1-(2-trimethylsilanyl-ethoxymethyl)-1,2,3,4-tetrahydro-2λ6-2,1-benzothiazin-3-yl]-piperidine-1-carboxylic acid tert-butyl ester (865 mg, 1.7 mmol) was dissolved in methanol (25 mL). Mixture was cooled to 0° C. Sodium borohydride (100 mg, 2.6 mmol) was added to the mixture in three portions. Reaction stirred at 0° C. for 3 hours. Mixture was concentrated by roto-vap. Residue was treated with 1N hydrochloric acid. Material was extracted twice with ethyl acetate. Organic phase was dried (magnesium sulfate), filtered and concentrated to dryness. Residue was dissolved in benzene (20 mL). p-Toluenesulfonic acid monohydrate (475 mg, 2.5 mmol) was added to the mixture. Reaction was heated to reflux and held with stirring for 1 hour. Mixture was cooled to room temperature. Solids were filtered off. The sticky solid was treated with hot isopropyl alcohol (10 mL). Mixture was cooled to room temperature and allowed to stand overnight. Solids were filtered off, washed with isopropyl alcohol and then dried under high vacuum. Title compound was obtained as tan solid in 65% yield. MS m/e (M+H)+=265.2.

Provenance & Evidence