1-Methylimidazole → 2-amino-5-(1-methyl-1H-2-imidazolyl)-1-benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-methylimidazole (4.8 ml, 60 mmol) in dry THF (120 ml) at −78° C. was added n-BuLi (2.5 M in hexane, 26 ml, 65 mmol) and the yellow mixture was stirred for 45 min at −78° C. A solution of ZnCl2 (2M in THF, 75 ml, 150 mmol) was added slowly and the cooling bath was removed. The colorless solution was stirred for another 10 min at 0° C. 5-Iodo-2-aminobenzenesulfonamide (see compound 37) (2.1 g, 7 mmol) and Pd(PPh3)4 (0.5 g, 5 mol %) was added and the mixture was refluxed for 6 h. The THF was evaporated and the residue was treated with EDTA (53 g, 0.18 mol) and made slightly basic (pH=8-9) with 1 M NaOH followed by extraction with EtOAc (3×150 ml), drying (Na2SO4) and evaporation of the solvent gave a dark oil. Flash-chromatography with 5% MeOH in CH2Cl2 as eluent gave 1.33 g (75%) of 2-amino-5-(1-methyl-1H-2-imidazolyl)-1-benzenesulfonamide as colorless crystals. The product was further transformed by Method G (using cyclohexanecarboxaldehyde). M.p. >250° C. (decomp).

Provenance & Evidence