p-Toluenesulfonic acid → HCID 54498235, compound

Temperature

0 °C

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.

1. temperaturewere refluxed with a Dean-Stark trap for 18 hours
2. concentrationThe reaction mixture was concentrated in vacuo
3. dissolutionthe residue dissolved in 50 ml of dry tetrahydrofuran
4. additionTo the resulting solution was added 945 mg of sodium borohydride over a period of 20 minutes
5. additionwas hydrolyzed by the addition of an ammonium chloride solution
6. concentrationwas concentrated to a small volume in vacuo
7. additionThe residual suspension was added to 200 ml of water
8. extractionthe resulting mixture extracted with ethyl acetate (2×200 ml)
9. washwashed with water
10. dry with materiala brine solution and dried over magnesium sulfate
11. customRemoval in vacuo of the solvent

ORD record

ord-e76be5689c7345fabd0f612ba61cc0c8

Source dataset

uspto-grants-1994_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05322847