Hydrochloric Acid → 2-(N,N-dimethylsulphamoyl)benzeneboronic acid

Participants

Reaction Conditions

Reaction Steps

A solution of N,N-dimethylbenzenesulfonamide (9.25 g; 50 mmol) in dry Et2O (150 ml) under N2 was cooled to −70° C. and added a solution of 2.5 M n-BuLi in hexane (24 ml; 60 mmol) such that the reaction temperature was kept below −60° C. The cooling bath was removed and the reaction mixture allowed to slowly warm up to +20° C. The reaction mixture was re-cooled to −70° C. and B(Oi-Pr)3 (16.1 ml; 70 mmol) was added. The reaction mixture was left cold and allowed to warm up over night, 1 M HCl (100 ml) was added and stirring was continued at rt. for 1 h. The reaction mixture was then extracted with Et2O (2×50 ml) and the combined organic fractions extracted with 1 M NaOH (4×50 ml). The combined aqueous fractions were neutralized with 1 M HCl and extracted with Et2O (4×100 ml). The combined organic fractions were dried (Na2SO4) and evaporated to dryness, washed with Et2O/hexane to give 3.4 g (30%) product.

Provenance & Evidence