Process for the manufacture of a crystalline pyrazolo[1,5-a]pyrimidine compound

A process for the industrial manufacture of polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide comprising the following steps:

• (i) reacting (5-amino-1H-pyrazol-4-yl)-thiophen-2-yl-methanone with N-[5-(3-dimethylamino-acryloyl)-2-fluoro-phenyl]-N-methyl-acetamide in a solvent selected from the group consisting of acetic acid, propionic acid, and formic acid at a temperature ranging from 50° C. to the boiling point of the mixture
• (ii) adding a (C1-C4)-alcohol;
• at a temperature comprised between 40° C. and 80° C.;
• (iii) aging for at least 30 min. at a temperature comprised between 30° C. and 55° C. to initiate the crystallization;
• and
• (iv) recovering the crystallized product.