Ethylene Glycol → Bosentan

Participants

Reaction Conditions

Reaction Steps

10 gms of p-tert-butyl-N-[6-chloro-5-(2-methoxy-phenoxy)-[2,2′-bipyrimidin]-4-yl]benzenesulfonamide potassium salt and barium hydroxide (1.5 gms) were charged to a reaction vessel. Ethylene glycol (30 ml) and toluene (150 ml) were added thereto. The reaction mass was heated at a temperature of 110° C. for 2 hours. Further 1.5 gms of barium hydroxide was added and heating was continued for another 4 hours. After completion of the reaction, toluene was removed by distillation and water (150 ml) was added. The pH of the reaction mass was adjusted to a value ranging from 1 to 2 with a mixture of 1:1 HCl:water and extracted in dichloromethane. The organic layer was collected and washed with water (150 ml) and the solvent was distilled off to obtain a residue. To the residue a mixture of ethanol and water (1:1) was added and stirred. The resulting suspension was heated to reflux to obtain a clear solution. The clear solution was further cooled to 25° C. to isolate bosentan.

Provenance & Evidence