An efficient method for the synthesis of pharmaceutically prospective pyrrole–aminopyrimidine ensembles (in up to 91% yield) by the cyclocondensation of easily available acylethynylpyrroles with guanidine nitrate has been developed. The reaction proceeds under heating (110–115 °C, 4 h) in the KOH/DMSO system. In the case of 2-benzoylethynylpyrrole, the unexpected addition of the formed pyrrole–aminopyrimidine as N- (NH moiety of the pyrrole ring) and C- (CH of aminopyrimidine) nucleophiles to the triple bond is observed.

Available pyrrolylalkynones with tetrahydroindolyl, cycloalkanopyrrolyl, and dihydrobenzo[g]indolyl moieties, acylethynylcycloalka[b]pyrroles, are readily annulated with Δ¹-pyrrolines (MeCN/THF, 70 °C, 8 h) to afford a series of novel pyrrolo[1′,2′:2,3]imidazo[1,5-a]indoles and cyclohepta[4,5]pyrrolo[1,2-c]pyrrolo[1,2-a]imidazoles functionalized with an acylethenyl group in up to an 81% yield. This original synthetic approach contributes to the arsenal of chemical methods promoting drug discovery. Photophysical studies show that some of the synthesized compounds, e.g., benzo[g]pyrroloimidazoindoles, are prospective candidates for TADF emitters of OLED.

1H-Indole and 2-methyl-1H-indole reacted with ethyl 3-bromopropynoate over aluminum oxide to give mixtures of the corresponding ethyl 3-(1H-indol-3-yl)propynoates and ethyl 3,3-bis(1H-indol-3-yl)-acrylates, the latter prevailing.

The title compound, 4,4-difluoro-3-(3-phenylisoxazol-5-yl)-8-trifluoromethyl-5-(2-naphthalen-2-yl)-4-bora-3a,4a-diaza-s-indacene (1), was synthesized for the first time in a 62% yield by the P₂O₅-promoted condensation of 2,2,2-trifluoro-1-[5-(naphthalen-2-yl)-1H-pyrrol-2-yl]-ethan-1-ol (2) with 3-phenyl-5-(1H-pyrrol-2-yl)isoxazole (3) followed by the oxidation of dipyrromethane 4 and the complexation of dipyrromethene thus formed with BF₃. The product fluoresces in a long wave region (651–662 nm) with a high quantum yield (0.49–0.61).

The title compound, 4-amino-5-benzoyl-1-benzyl-2-(4,5,6,7-tetrahydro-1H-indol-2-yl)- 1H-pyrrole-3-carbonitrile, was synthesized for the first time in a 40% yield by the reaction of N-benzyl-3-imino-5,6,7,8-tetrahydro-3H-pyrrolo[1,2-a]indol-1-amine and 1-chloroacetophenone in a K₂CO₃/MeCN system (reflux, 6 h). The product was characterized by ¹H-NMR, ¹³C-NMR, IR spectroscopy, and elemental analysis.