<i>Michael</i> Reactions of α-Unsubstituted Trisubstituted 1/<i>H</i>-Pyrroles

To obtain stable derivatives of α-unsubstituted pyrroles, the reaction of the test pyrrole <b>9</b> with a series of chalcones <b>14a-h</b> were studied. Michael adducts <b>16b-h</b> could be isolated. In order to synthesize coloured derivatives, the reaction of different pyrroles <b>9</b>, <b>2</b>1, <b>23</b>, and <b>25</b> with diphenylpropynone <b>19</b> was investigated. In these cases, too, <b>Michael</b>-addition products were formed. The intense absorption band around 400 nm makes the identification of these derivatives easy.