4-(((1-Propylimidazol-5-yl)methyl)sulfinyl)aniline di-p-toluoyl-D-tartarate monohydrate → 4-[[(1-Propyl-1H-imidazol-5-yl)methyl]sulfinyl]benzenamine

Participants

Reaction Steps

(−)-4-(((1-Propylimidazol-5-yl)methyl)sulfinyl)aniline di-p-toluoyl-D-tartarate monohydrate (6.58 g) was dissolved in ethyl acetate (50 ml) and 1N hydrochloric acid (33.5 ml), followed by separation. To the aqueous layer was added an aqueous 25% potassium carbonate solution (33.5 ml), followed by extraction with 2-propanol-ethyl acetate (1:4) twice. The organic layers were combined and washed with saturated brine, dried with magnesium sulfate, and the solvent was distilled off under reduced pressure. To the resulting residue tetrahydrofuran was added, after which the solvent was distilled off again under reduced pressure to give (−)-4-(((1-propylimidazol-5-yl)methyl)sulfinyl)aniline. Then, to a solution of 8-(4-(2-butoxyethoxy)phenyl)-1-formyl-1,2,3,4-tetrahydro-1-benzoazocine-5-carboxylic acid (3.0 g) in tetrahydrofuran (30 ml) was added a drop of DMF, and then oxalyl chloride (0.86 ml) was added, and the mixture was stirred under nitrogen atmosphere for 1 hour. The resulting solution was added dropwise to a solution of (−)-4-(((1-propylimidazol-5-yl)methyl)sulfinyl)aniline and pyridine (16 ml) in tetrahydrofuran (70 ml) at 0° C. under nitrogen atmosphere. The mixture was returned to room temperature and stirred for 3 hours, after which water was added and extracted with ethyl acetate. The organic layer was washed with 10% aqueous acetic acid solution twice, with aqueous saturated sodium bicarbonate solution twice, and with saturated brine once, after which the resultant was dried with magnesium sulfate. After distilling off the solvent under reduced pressure, the resultant was separated and purified with a basic silica gel column chromatography (methanol:ethyl acetate=1:25) to give (−)-8-[4-(2-butoxyethoxy)phenyl]-1-formyl-N-[4-[[[1-propylimidazol-5-yl]methyl]sulfinyl]phenyl]-1,2,3,4-tetrahydro-1-benzoazocine-5-carboxamide (3.34 g) (Compound 29) as a yellow amorphous material.

Provenance & Evidence