Hydrochloric Acid → Trifluoromethanesulfonic acid 5-amino-5,6,7,8-tetrahydronaphthalen-2-yl ester

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Reaction Steps

A solution of trifluoro-methanesulfonic acid 5-azido-5,6,7,8-tetrahydro-naphthalen-2-yl ester (Step C, 10.3 g, 32.1 mmol, 1.0 eq) in THF (70 mL) was added PPh3 (Aldrich, 8.4 g, 32.1 mmol, 1.0 eq), and H2O (30 mL) at 0° C. The mixture was warmed to RT and stirred overnight. 2 N HCl was added until the mixture was acidic (pH ˜1-2). The mixture was extracted with toluene (3×100 mL). The aqueous phase was neutralized with 5 N NaOH to pH around 12-13, and extracted with ether (3×150 mL). The ether solution was dried over Na2SO4 filtered and concentrated in vacuo. The crude was purified by flash chromatography (6% MeOH—CH2Cl2) to provide the title compound.

Provenance & Evidence