Aniline → HCID 66718671, compound

Participants

Reaction Conditions

Reaction Steps

9.31 g Aniline is added to a mixture of 50 g ice and 29.4 ml aqueous HCl (32% w/w). Then, a solution of 6.90 g NaNO2 in 30 ml water is slowly added while keeping the temperature between −5 and 0° C. To this solution, a cold (−5° C.) solution of 15.7 g 2,2,6,6-tetramethyl-4-hydroxypiperidine in 30 ml water and 9.8 ml aqueous HCl (32% w/w) and a cold solution of 16 g NaOH in 40 ml water are slowly added sequentially while keeping the temperature in the range from −5 to 0° C. The thick brown suspension is allowed to warm up to 23° C. and is then diluted with 100 ml dichloromethane. The organic phase is separated, evaporated and chromatographed on silica gel with hexane-ethylacetate (2:1) to afford 17.4 g of 2,2,6,6-tetramethyl-1-phenyldiazenyl-piperidin-4-ol as a slightly yellow oil which solidifies on standing. A sample of this material is recrystallized from dichloromethane-hexane to afford light yellow solid, m.p. 68-70° C.

Provenance & Evidence