p-Toluenesulfonic acid → HCID 54498235, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 1.38 g of 3-hydroxymethylbenzaldehyde, 1.7 g of 2-amino-5-fluorobenzothiazole and 200 mg of p-toluene sulfonic acid in 100 ml of toluene were refluxed with a Dean-Stark trap for 18 hours. The reaction mixture was concentrated in vacuo and the residue dissolved in 50 ml of dry tetrahydrofuran and 50 ml of methanol and cooled to 0° C. To the resulting solution was added 945 mg of sodium borohydride over a period of 20 minutes. The reaction mixture was stirred at 0° C. for 2 hours, was hydrolyzed by the addition of an ammonium chloride solution and was concentrated to a small volume in vacuo. The residual suspension was added to 200 ml of water, the pH adjusted to 10 and the resulting mixture extracted with ethyl acetate (2×200 ml). The extracts were combined, washed with water and a brine solution and dried over magnesium sulfate. Removal in vacuo of the solvent gave 2 g of material which was chromatographed on silica gel to give 235 mg of pure product.

Provenance & Evidence