26673-31-4

6-Chloro-1-tetralone is a novel and potent intermediate used for synthesis of pharmaceutical compounds.

A solution of sodium nitrite (173 mg, 2.51 mmol) in water (5 mL) at 0 °C (ice-bath) was added to a magnetically stirred suspension of 6-Amino-1-tetralone (360 mg, 2.23 mmol) in aqueous hydrochloric acid (10 mL, 6 M) at 0 °C. This reaction mixture was added dropwise to a solution of copper(I) chloride (267 mg, 2.70 mmol) in concentrated hydrochloric acid (5 mL) at 0 °C. It was allowed to warm up to room 100 temperature and stirred for a further 2 h after which it was neutralised with solid sodium carbonate, extracted with ethyl acetate (3 × 20 mL) and concentrated in vacuo to give slightly yellow oil. This material was subjected to flash chromatography (50% chloroform in hexane) and concentration of the appropriate fractions afforded 6-chloro-1-tetralone  (180 mg, 45%) as a waxy solid.