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.
[1] Patent: US2015/105351, 2015, A1. Location in patent: Paragraph 0440
[2] ACS Medicinal Chemistry Letters, 2014, vol. 5, # 11, p. 1259 - 1262
[3] Organic Letters, 2011, vol. 13, # 24, p. 6488 - 6491
[4] Patent: US2012/302562, 2012, A1. Location in patent: Page/Page column 21
[5] Australian Journal of Chemistry, 2010, vol. 63, # 2, p. 211 - 226
