Synthesis of alkyl substituted 1H-pyrrole and N-substituted pyrroles using ketonic mannich bases

Synthesis of pyrrole compounds is important for the synthetic organic chemistry and medicinal chemistry because of their existence in living systems and biological activities. Some antiinflamatuar, antifungal, antibacterial, anticancer drugs include alkyl pyrrole derivatives as active pharmaceutical ingredient. Ketonic Mannich bases are obtained from the aminonalkylation of active hydrogen-bearing ketones. They are commonly used in pharmaceutical chemistry. Ketonic Mannich bases which are more stable than enones which are used in chemical reactions as enone precursor instead of less stable enone compounds. In this study, ketonic Mannich bases were firstly synthesized from ketones with different aryl groups by using Mannich reaction. The addition reactions of 1H-pyrrole, 1-methylpyrrole and 1-phenylpyrrole to enones, obtained from the deamination of ketonic Mannich bases, were carried out in water without catalyst. A series of new or known mono-substituted and disubstituted alkyl pyrrole compounds were synthesized in good to high yields with this applied green method. Structures of the obtained compounds were described by 1H NMR, 13C NMR and HRMS techniques.