Mass-spectral behavior and thermal stability of hetaryl analogs of unsymmetrical benzoins

Abstract

The main path in the mass-spectral dissociation of the hetaryl analogs of unsymmetrical benzoins is β-fragmentation with cleavage of the central C-C bond. Here, the strongest peak in the mass spectra of α-benzoins is the peak of the hydroxymethylhetaryl cation, and in β-benzoins it is the peak of the hetaroyl cation. The thermal α → β isomerization of the hetaryl analogs of benzoin was studied. In the case of indole and pyrrole derivatives the formation of polyheterocyclic systems is observed.

Synthesis and Structure of 3,4,5-Trihydroxy-5-(4-Nitrophenyl)imidazolidin-2-One

“…In mass spectrum cation C [M+H-H2O] + (m/z 244), 4nitrobenzoyl cation D (m/z 150) and "benzylic" furyl cation E (m/z 111) dominate (Scheme 7), which is typical for αbenzoins. 6,8,10,14,15 Scheme 7. Fragmentation pattern of 2-hydroxy-2-(5-methylfuran-2-yl)-1-(4-nitrophenyl)ethanone (5e) (FAB)…”

Arylglyoxals in Synthesis of Heterocyclic Compounds

“…When the pyrrole 635 was heated at 150 °C, tetramerization occurred, and the porphyrin 638 was isolated. In the case of the indole 636 (R = H), the dimer 639 is isolated in a small yield, whereas the N -methylindole 636 (R = Me) resulted in a high yield of the dimer 639 (Scheme ) …”

“…In the case of the indole 636 (R = H), the dimer 639 is isolated in a small yield, whereas the N-methylindole 636 (R = Me) resulted in a high yield of the dimer 639 (Scheme 193). 711…”

Synthesis of Linearly Fused Benzodipyrrole Based Organic Materials

“…When the non-alkylated indole is used, only 10% of the dibenzoylated indolo[3,2- b ]carbazole 27 is obtained. By using N -methylated indole for this reaction, the yield is increased up to 91% (Scheme 8) [30].…”