Compounds of formula I: or salts thereof are disclosed. Also disclosed are pharmaceutical compositions comprising a compound of formula I, processes for preparing compounds of formula I, intermediates useful for preparing compounds of formula I and therapeutic methods for treating a Retroviridae viral infection including an infection caused by the HIV virus.本發明揭示式I之化合物:或其鹽類。本發明也揭示包含式I之化合物的藥學組成物,供製備式I之化合物的方法,用於製備式I之化合物的中間物,及供治療反轉錄病毒科(Retroviridae)病毒感染之治療法,該病毒感染包括由HIV病毒所引起的感染。