"or preferably by lower alkyl, such as by tert-butyl or especially by methyl, or 1H-tetrazol-5-yl substituted by tert-butyl or especially by methyl; pyridinyl; pyrazinyl; and pyrimidinyl; more especially 2- or 3-thienyl (=thiophen-2-yl or thiophen-3-yl);" . . . .