6-Aryl-pyrrolo[1,2-a]Imidazole derivatives which possess anti-hypertensive activity

#This invention relates to novel heterocyclic compounds and more particularly it relates to novel 6-arylpyrrolo[1,2-a]imidazole derivatives which possess antihypertensive activity.

#According to the invention there is provided a compound of the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.5, which may be the same or different, each stands for the hydrogen atom or for an alkyl radical of up to 4 carbon atoms, and wherein either R.sup.4 stands for the hydrogen atom or for an alkyl radical of up to 4 carbon atoms and Ar stands for an aromatic nucleus which may optionally bear one or more substituents, or Ar stands for an aromatic nucleus which bears a substituent in the position adjacent to the linking position which substituent together with the substituent R.sup.4 forms an alkylene radical of up to 3 carbon atoms, and which nucleus Ar may optionally bear one or more further substituents; or an acid-addition salt thereof.

#It will be observed that the compound of the invention possesses at least one asymmetric carbon atom, namely that at the 6- position of the pyrrolo[1,2-a]imidazole which is numbered as follows: ##STR2## and that it may possess more than one asymmetric carbon atom if any one of the substituents R.sup.1, R.sup.2, R.sup.3 and R.sup.5 stands for an alkyl radical. The compound will therefore exist in at least one racemic and at least one pair of optically-active forms. It is to be understood that the invention encompasses the racemic form and any optically-active form which possesses antihypertensive activity, it being a matter of common general knowledge how a racemic compound may be separated into its optically-active forms and how the antihypertensive activity of any particular form may be measured.