Aluminium lithium hydride → 2-Chloro-4-mercaptophenol

Lithium aluminium hydride (as a 1M solution in tetrahydrofuran, 71.0 ml, 71.0 mmol) was added dropwise to an ice cold solution of 3-chloro-4-hydroxyphenyl thiocyanate (4.20 g, 22.6 mmol) in tetrahydrofuran (100 mL) under nitrogen. The reaction mixture was stirred and allowed to warm to room temperature over 5 hours. The mixture was cooled to 5° C. and quenched with a 1:1 mixture of tetrahydrofuran:water until no more gas evolution was seen. 1N hydrochloric acid solution in water (30 mL) was then added, and the mixture extracted with ethyl acetate (2-fold 70 mL). The combined organic layers were dried (sodium sulphate) and concentrated in vacuo affording a colourless crystalline solid, 100% yield, 3.60 g.