| abstract |
The present invention provides compounds of formula (2):n and their pharmaceutically acceptable salts which are useful as histamine H 1 -antagonists. In formula (2) R' is halogen or nitro; R' is C 1-4 alkyl: R 3 is a C 1-3 alkylene group; and R 4 is 3-pyridyl; N-oxo-3-pyridyl; 6-methyl-3-pyridyl; N-oxo-6-methyl-3-pyridyl; 6-hydroxymethyl-3-pyridyl; 4,6-dimethyl-3-pyridyl; N-oxo-4.6-dimethyl-3-pyridyl; 6-hydroxymethyl-4-methyl-3-pyridyl; 5,6-dimethyl-3-pyridyl; N-oxo-5,6-dimethyl-3-pyridyl; 6-hydroxymethyl-5-methyl-3-pyridyl; 4-pyridyl or N-oxo-4-pyridyl. |