The invention relates to a preparation method of small-particle-size
macitentan, and belongs to the technical field of
raw material medicine preparation. According to the preparation method of the small-particle-size
macitentan, firstly, an
macitentan crude product is dissolved in an isopropanol-n-
heptane mixed
solvent, and filtering is conducted; then obtained filter liquid is cooled to 5 to 15 DEG C, the temperature is maintained, under stirring,
acetone with volume 0.8-1.2 times of that of the
solvent in the first step is added in a flowing mode, stirring speed is 200-230 rpm, the speed ofadding the
acetone in a flowing mode is 8-12 ml / min, and after flowing adding is completed, stirring is conducted continuously for 3-5 hours; filtering is conducted, and
drying is conducted at 50-60 DEG C. The invention provides the preparation method of the small-particle-size macitentan. The prepared macitentan D90 can be controlled to be between 3.5 micrometers and 38.06 micrometers, and a rawmaterial
medicine which can be used directly is provided for an macitentan preparation.