Boron trifluoride etherate → HCID 15101108, compound

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Reaction Steps

A solution of (±)-1-[(2-amino-4,5,6,7-tetrahydro-6-benzothiazolyl)carbonyl]-4-(2-pyridinyl)-piperazine (2.8 g) (Example 6) in 200 ml of anhydrous tetrahydrofuran is treated with sodium borohydride (1.0 g) under nitrogen. The mixture is cooled in an ice bath and treated with boron trifluoride etherate (3.93 ml) dropwise. The reaction mixture is stirred at room temperature overnight, and quenched with 5 ml of glacial acetic acid. The mixture is evaporated in vacuo and the residue dissolved in 200 ml of a 10% solution of hydrochloric acid and refluxed for about 30 minutes. The solution is cooled in an ice bath and made basic with a concentrated solution of ammonium hydroxide and extracted with chloroform. The organic extract is dried (magnesium sulfate) and evaporated. The residue is triturated with 50 ml of warm diethyl ether and, after cooling to room temperature, is filtered. The title compound is obtained as a colorless solid; mp 177°-179° C.

Provenance & Evidence