| 摘要 |
The present invention provides compounds of formula (1):-
<CHEM>
and pharmaceutically acceptable salts thereof where
R<1> and R<2> are the same or different and are hydrogen, C1-6 alkyl, C1-6 alkoxy, or halogen;
R<3> is C1-6 alkyl, C3-8 cycloalkyl C1-6 alkyl, optionally substituted phenyl or optionally substituted phenyl C1-6 alkyl, where the optional substituents are one or more C1-6 alkyl, C1-6 alkoxy, halogen, or hydroxy groups; or is optionally substituted pyridyl or optionally substituted pyridyl C1-6 alkyl where the optional substituents are one or more C1-6 alkyl or C1-6 alkoxy groups or halogen atoms;
a is from 2 to 4
b is from 1 to 6
R<4> is hydrogen, optionally substituted phenyl where the optional substituents are one or more C1-6 alkyl, C1-6 alkoxy, nitro or hydroxy groups or halogen atoms, or a methylenedioxy group,
or is an optionally substituted pyridyl group where the optional substituents are one or more C1-6 alkyl, C1-6 alkoxy groups or halogen atoms;
or is a C3-8 cycloalkyl group; or is N-oxo-3-pyridyl; N-oxo-6-methyl-3-pyridyl,
6-hydroxymethyl-3-pyridy; N-oxo-4,6-dimethyl-3-pyridyl; 6-hydroxymethyl-4-methyl-3-pyridyl, N-oxo-5,6-dimethyl-3-pyridyl; 6-hydroxymethyl-5-methyl-3-pyridyl; or N-oxo-4-pyridyl, or is a pyridone group in which the nitrogen atom is optionally substituted with C1-6 alkyl. The compounds of this invention are useful as histamine H1-antagonists. |
