[Cardiovascular action of 1,2,4-benzothiadiazine-1,1-dioxide derivatives. VII]

A series of dimethylamino-, diethylamino-, pyrrolidyl- and morpholylalkyl derivatives of 3-amino-1,2,4-benzothiadiazine-1,1-dioxide (compounds I leads to XX) was prepared and tested for cardiovascular activity. It was found that substitution of the alkyl group with the above mentioned groups in 3-amino-1,2,4-benzothiadiazine-1,1-dioxide derivatives in most cases causes marked dissociation of hypotensive activity from bradycardial activity and also disappearance or great reduction in the effect on differential pressure. It was also found that hypotensive activity is particularly dependent on the nature of the basic chain in the two components: length of the carbon chain between the two nitrogens and nature of the basic grouping. For the first component a chain of three carbon atoms seems the most effective and for the second the diethylamino group seems the most favourable. In addition, substituents in the benzene ring influence hypotensive activity, often positively, and 6,7-dichlorosubstitution in some compounds also affects the increase of differential pressure.