Trifluoroacetic acid → HCID 21916947, compound

Participants

Reaction Conditions

Reaction Steps

A solution of the product obtained in Step F (20 mmol) in dichloromethane (30 ml) containing tetrabutylammonium bromide (20 mg) is cooled in an ice-bath. After the addition of sodium azide (25 mmol) dissolved in 5 ml of water, the solution is stirred vigorously at 0° C. for 2 hours. The organic phase is separated off, washed with water (2×5 ml) and dried over magnesium sulphate. After filtration, trifluoroacetic acid (30 mmol) is added and the solution is stirred under reflux for 60 hours. After cooling, the organic phase is washed with a saturated sodium hydrogen carbonate solution (2×5 ml) and concentrated under reduced pressure. The residue is then taken up in methanol (20 ml), and water (80 ml) and then potassium carbonate (30 mmol) are added. After stirring at ambient temperature for 20 hours, the reaction mixture is concentrated under reduced pressure to a volume of about 60 ml, and is then extracted 3 times with ether (3×50 ml). After drying over sodium sulphate, the organic phase is filtered and then evaporated under reduced pressure. The residue is chromatographed on silica gel to yield the title product.

Provenance & Evidence