FURO [3,2-B] PYRROL-3-ONE DERIVATIVES AND THEIR USE AS CYSTEINYL PROTEINASE INHIBITORS

摘要

The present invention relates to compounds of formula (I), and pharmaceutically acceptable salts thereof (I), wherein: R<SUP>3</SUP> is cyclopentyl or cyclohexyl; X is CH or N; and R<SUP>4</SUP> is optionally substituted C<SUB>1-8</SUB> alkyl or optionally substituted C<SUB>3-8</SUB> cycloalkyl. The invention further relates to pharmaceutical compositions comprising compounds of formula (I), and the use of such compounds in the treatment of a disease selected from osteoporosis, Paget' s disease, Chagas's disease, malaria, gingival diseases, hypercalaemia, metabolic bone disease, diseases involving matrix or cartilage degradation, and bone cancer disorders such as bone metastases and associated pain.