Denisa Dumitrescu

Synthesis of Pyrrolo[2,1-a]isoquinolines by Multicomponent 1,3-Dipolar Cycloaddition

Pyrrolo[2,1-a]isoquinoline derivatives were synthesized by one-pot three-component reactions starting from isoquinoline, 2-bromoacetophenones and different non-symmetrical acetylenic dipolarophiles using 1,2-epoxypropane as solvent. The structure of the compounds was assigned by IR and NMR spectroscopy.

Synthesis and X-ray Structure of a New Pyrrolo(1,2-b)- pyridazine Derivative

The synthesis, characterization and X-ray crystal structure of 2-(4-chloro-phenyl)-7-methylpyrrolo[1,2-b]pyridazine are reported. The compound crystallizes in the space group P21/c (No.14) with a =3.8568(1), b = 11.0690(3), c = 26.4243(7) Å, β = 92.777(1)° and Z = 4. Accurate molecular parameters for the novel heterocyclic system were obtained from intensity data collected at 113K. The molecule assumes a planar conformation in the crystal and the packing is based on π-π stacking with interplanar spacing 3.400 Å, typical of aromatic molecules with potential for displaying useful optical properties.

Sydnone C-4 heteroarylation with an indolizine ring via Chichibabin indolizine synthesis

The synthesis of sydnones heteroarylated at C-4 with an indolizine was achieved by Chichibabin (Tschitschibabin) indolizine synthesis starting from the corresponding sydnone-N-pyridinium bromides. The latter compounds were also transformed to sydnone-indolizines connected through a keto group at the C-4 position by refluxing them in 1,2-epoxybutane with an activated alkyne. The structures of the new compounds were assigned by FTIR, NMR spectroscopy and X-ray analysis.

Coumarin substituted pyrrolo-fused heterocyclic systems by 1,3-dipolar cycloadditon reactions

A variety of new pyrrolo-fused heterocyclic systems bearing a 3-carbonylchromen-2-one moiety on the pyrrole rings was obtained based on 1,3-dipolar cycloaddition reactions of corresponding cycloimmonium-ylides, generated in situ from the quaternary salts of several N-heterocycles with 3-(2-bromoacetyl)-2H-chromen-2-one, with electron-deficient alkynes. The synthetic strategies were both one-pot, three-component and classical multistep 1,3-dipolar cycloaddition reactions. The all newly synthesized compounds were structurally characterized by elemental analysis, IR and NMR spectroscopy.Graphical abstract

Reaction of 4-hydroxycoumarin or its O-substituted derivatives with diatomic interhalogens: ICl and IBr

ABSTRACT Herein, we present some aspects regarding the iodination/bromination of 4-hydroxycoumarin or its O-methyl or O-acetyl derivatives with iodine monochloride or iodine monobromide as halogenation reagents. Also, the investigation of photochemical transformation of the three 3-iodocoumarins was investigated for the first time. GRAPHICAL ABSTRACT