PYRAZOLO[3,4-b]PYRIDINE COMPOUNDS, AND THEIR USE AS PDE4 INHIBITORS

摘要

The invention relates to a compound of formula (I) or a salt thereof: formula (I) wherein: R<1> is Et, n-Pr, i-Pr, C2fluoroalkyl, or -CH2CH2OH; R<2> is H, Me, Et, n-Pr, i-Pr, C1-2fluoroalkyl, cyclopropyl or (cyclopropyl)methyl-; and NHR<3> has the sub-formula (nhr3): formula (nhr3) wherein R<3a> is methyl or ethyl; R<3b> is H, methyl or ethyl; R<3c> is H, methyl or ethyl, R<3d> is H, methyl or ethyl, and R<3e> is H or methyl, provided that: (a) R<3b> is methyl or ethyl; and/or (b) R<3c> and R<3d> are independently methyl or ethyl; and provided that: (c) when R<3c> is ethyl and/or when R<3d> is ethyl and/or when R<3e> is methyl, then: R<3a> is methyl and/or R<3b> is a hydrogen atom (H) or methyl. NHR<3> can for example be [(1S)-1,2-dimethylpropyl]amino or t-butylamino. The invention also relates to the use of these pyrazolo[3,4 b]pyridine compounds in therapy, as inhibitors of phosphodiesterase type IV (PDE4), and relates to their use in the treatment and/or prophylaxis of inflammatory and/or allergic diseases such as chronic obstructive pulmonary disease (COPD), asthma, rheumatoid arthritis or allergic rhinitis.