Purine derivatives having phosphodiesterase IV inhibition activity

A pharmaceutical composition comprising a pharmaceutically acceptable arrier and a compound of the formula (III):

• wherein
• R3 represents a C1-8 alkyl which is unbranched or branched and unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2, or ═O;
• C3-8 cycloalkyl which is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, halogen, C1-10 haloalkyl, CO2H, ═NOH, ═NOCONH2, or ═O;
• C4-8 cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2,or ═O;
• aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8 alkylamido, C1-C3 dialkylamido, OH, C1-6 alkoxy, C3-6 cycloalkoxy, CH═NOH, CH═NOCONH2, C1-C3 alkyl, phenyl or benzyl;
• aralkyl (C1-4), optionally substituted with halogen, C1-C4 alkyl, nitro, trifluoromethyl, C1-C6 alkoxy or C3-C6 cycloalkoxy;
• a five to seven membered heterocyclyl ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms;
• and heterocyclylalkyl (C1-C4) wherein said heterocyclyl moiety is a five to seven membered ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms;
• R8 represents H or a C1-8 alkyl which is unbranched or branched and unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2, or ═O;
• C3-8 cycloalkyl which is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, halogen, C1-10 haloalkyl, CO2H, ═NOH, ═NOCONH2, or ═O;
• C4-8 cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2,or ═O;
• aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8 alkylamido, C1-C3 dialkylamido, OH, C1-6 alkoxy, C3-6 cycloalkoxy, CH═NOH, CH═NOCONH2, C1-C3 alkyl, phenyl or benzyl;
• aralkyl (C1-4), optionally substituted with halogen, C1-C4 alkyl, nitro, trifluoromethyl, C1-C6 alkoxy or C3-C6 cycloalkoxy;
• a five to seven membered heterocyclyl ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms;
• and heterocyclylalkyl (C1-C4) wherein said heterocyclyl moiety is a five to seven membered ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms.

A method of treating a mammal suffering from a disease state selected from the group consisting of asthma, allergies, inflammation, depression, atopic diseases and rhinitis, comprising administering to the mammal an effective amount of a compound of the formula (III):

• wherein
• R3 and R8 are the same or different and each represent H or a C1-8 alkyl which is unbranched or branched and unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2, or ═O;
• C3-8 cycloalkyl which is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, halogen, C1-10 haloalkyl, CO2H, ═NOH, ═NOCONH2, or ═O;
• C4-8 cycloalkylalkyl wherein the cycloalkyl portion is unsubstituted or substituted with OH, C1-6 alkoxy, C3-6 cycloalkoxy, CO2H, ═NOH, ═NOCONH2,or ═O;
• aryl which is unsubstituted or substituted with Cl, NH2, alkylamino, dialkylamino, amido, C1-C8 alkylamido, C1-C3 dialkylamido, OH, C1-6 alkoxy, C3-6 cycloalkoxy, CH═NOH, CH═NOCONH2, C1-C3 alkyl, phenyl or benzyl;
• aralkyl (C1-4), optionally substituted with halogen, C1-C4 alkyl, nitro, trifluoromethyl, C1-C6 alkoxy or C3-C6 cycloalkoxy;
• a five to seven membered heterocyclyl ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms;
• and heterocyclylalkyl (C1-C4) wherein said heterocyclyl moiety is a five to seven membered ring having at least one carbon atom and up to three nitrogen atoms, up to two oxygen atoms, and up to two sulfur atoms;
• and pharmaceutically acceptable salts thereof.