Compounds of formula (I): wherein R 1 is C 1-6 alkylamino, C 1-6 alkoxy, or C 3-7 cycloalkyloxy m is an integer having a value of 3 to 6 n is an integer having a value of 0 to 4 and salts thereof are inducers of human interferon. Compounds which induce human interferon may be useful in the treatment of various disorders, for example the treatment of allergic diseases and other inflammatory conditions for example allergic rhinitis and asthma, the treatment of infectious diseases and cancer, and may also be useful as vaccine adjuvants.
