Crystal form of key intermediate of bruton tyrosine kinase (btk) inhibitor and preparation method thereof

Abstract

The present disclosure relates to a crystal form of a key intermediate of a bruton tyrosine kinase (BTK) inhibitor and a method for preparing the crystal form, and belongs to the technical field of medicine. The crystal form is a crystal form II of (R)-1-(1-(tert-butyloxyl)pyrrolidine-3-yl)-3-cyano-4-(4-(2,6-difluorophenoxyl)phenyl)-1H-pyrrole-2-ethyl formate. The obtained crystal form II of (R)-1-(1-(tert-butyloxyl)pyrrolidine-3-yl)-3-cyano-4-(4-(2,6-difluorophenoxyl)phenyl)-1H-pyrrole-2-ethyl formate has good chemical stability and crystal form stability and is convenient for storage and transportation. Meanwhile, the intermediate can be highly purified and a sample with a purity of 99.7% is obtained. The crystal form is important for quality control of a BTK inhibitor (R)-4-amino-1-(1-(butyl-2-alkynyl)pyrrolidine-3-yl)-3-(4-(2,6-difluorophenoxyl)phen yl)-1,6-dihydro-7H-pyrrolo[2,3-d]pyridazin-7-one, has a simple preparation process and is suitable for industrial production.