Novel 1-hydroxy-1,1-bisphosphonates derived from indazole: synthesis and characterization

Abstract

Bisphosphonates (BPs) are an important class of drugs used in the treatment of abnormal calcium metabolism diseases. The first syntheses of bisphosphonates derived from indazole, substituted at the N-1, N-2 and C-3 positions are reported. The 1-hydroxy-1,1-bisphosphonates were synthesized from the corresponding carboxylic acid or acyl chloride compounds, by two different methods. These BPs have a side chain with different lengths ((CH2)n, n = 0-5) between the indazole ring and the bisphosphonate group.