2-Bromoaniline → HCID 66718653, compound

Participants

Reaction Steps

50 g crushed ice are added to a solution of 2-bromoaniline in 4 ml THF and 4 ml aqueous HCl (32% w/w). The yellow suspension is diazotized at −5° C. by treatment with a solution of 1.1 g sodium nitrite in 10 ml water. After 3 h, a solution of 2.76 g 2,2,6,6-tetramethyl-4-hydroxypiperidine in 1.5 ml aqueous HCl (32% w/w) and 1 ml THF are added dropwise to the thick yellow suspension at −3° C. Addition of water (ca. 20 ml) is necessary to keep the mixture well stirrable. The reaction mixture is then neutralized by adding dropwise 8.8 ml of aqueous sodium hydroxide (30% w/w) and 4 ml THF between 0 and 2° C. The brownish mixture is extracted with ethyl acetate. The organic phase is separated, evaporated and chromatographed on silica gel with hexane-ethylacetate (3:1), yielding 1.11 g of 1-(2-bromophenyl-diazenyl)-2,2,6,6-tetramethyl-piperidin-4-ol as a red-brown solid, m.p. 81° C.

Provenance & Evidence