The present invention provides a
bosentan preparation method, which comprises: mixing
phosphorus oxychloride and 5-(2-methoxyphenoxy)-[2, 2 '-dipyrimidine]-4, 6 (1H, 5H)-
diketone, and carrying out a reaction to obtain 4, 6-dichloro-5-(2-methoxyphenoxy)-2, 2'-dipyrimidine, and carrying out a reaction to obtain 4, 6-dichloro-5-(2-methoxyphenoxy)-2, 2 '-dipyrimidine, mixing the N-[6-chloro-5-(2-methoxyphenoxy)-4-pyrimidyl] benzenesulfonamide with 4-tert-butyl benzenesulfonamide, an acid-binding agent and a polar aprotic
solvent, and carrying out a reaction to obtain 4-tert-butyl-N-[6-chloro-5-(2-methoxyphenoxy)-4-pyrimidyl] benzenesulfonamide
potassium salt; then mixing the
bosentan precursor with
ethylene glycol,
alkali metal hydroxide and
tetrahydrofuran to obtain a
bosentan precursor; and finally, mixing with
ethanol and water, reacting, cooling and crystallizing to obtain bosentan. According to the preparation method of bosentan, the reaction time can be greatly saved, the reaction yield can be improved, the
impurity content can be reduced, the post-treatment operation can be simplified, the preparation cost can be reduced, and industrial large-scale production and application can be facilitated.