Selective cyclization modes of methyl 3′-heteroarylamino-2′-(2,5-dichlorothiophene-3-carbonyl)acrylates. Synthesis of model (thienyl)pyrazolo- and triazolo[1,5-α]pyrimidines

Interaction of methyl 3-ethoxy-2-(2,5-dichloro-3-thenoyl)acrylate (I) with 3-aminopyrazole and 3-amino-1,2,4-triazole generated the respective pyrazolo[1,5-α]pyrimidine (4) and triazolo[1,5-α]pyrimidine (7). The formation of 4 entails selective and consecutive displacement of the 3-ethoxy and methoxy (ester) anions in I by 3-NH2 and 1-NH of 3-aminopyrazole. On the other hand, the formation of 7 implies selective displacement of 3-ethoxy in I by the ring-NH followed by cyclocondensation involving the keto group in I and 3-NH2 of aminotriazole. This latter selective displacement sequence is also followed by 3-amino-5-hydroxypyrazole in its reaction with I. The structures of the new compounds are supported by microanalytical and spectral data.

Synthesis, characterization and electrochemical properties of meso-thiocarboxylate-substituted porphyrin derivatives

Considering the versatility of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF20) to react with nucleophiles we highlight here the synthesis and characterization of several mono- and tetra-thiocarboxylate derivatives. The selective displacement of the para-fluorine groups in TPPF20 by thiocarboxylic acids demonstrates that TPPF20 is an ideal platform for the rapid formation of thiocarboxylate porphyrins. The optical and electrochemical features of the thiocarboxylate derivatives were also examined thinking on their potential use in photovoltaic devices. From their electrochemical characterization the following parameters were taken into account: (i) electronegative induced effect of the thiocarboxylate dyes owing the presence of the fluorine and sulfur atoms on the molecular structure of the porphyrin; and (ii) the free rotation and flexibility features that such S atom gives to the porphyrin relatively to the semiconductor.

Inhibitory Inputs to Hippocampal Interneurons Are Reorganized in Lis1 Mutant Mice

Epilepsy and brain malformation are commonly associated with excessive synaptic excitation and decreased synaptic inhibition of principal neurons. However, few studies have examined the state of synaptic inhibition of interneurons in an epileptic, malformed brain. We analyzed inhibitory inputs, mediated by γ-aminobutyric acid (GABA), to hippocampal interneurons in a mouse model of type 1 lissencephaly, a neurological disorder linked with severe seizures and brain malformation. In the disorganized hippocampal area CA1 of Lis1+/− mice, we initially observed a selective displacement of fast-spiking, parvalbumin-positive basket-type interneurons from stratum oriens (SO) locations to s. radiatum and s. lacunosum-moleculare (R/LM). Next, we recorded spontaneous and miniature inhibitory postsynaptic currents (sIPSCs and mIPSCs) onto visually identified interneurons located in SO or R/LM of Lis1+/− mice and age-matched littermate controls. We observed significant, layer-specific reorganizations in GABAergic inhibition of interneurons in Lis1 mutant mice. Spontaneous IPSC frequency onto SO interneurons was significantly increased in hippocampal slices from Lis1+/− mice, whereas mIPSC mean amplitude onto these interneurons was significantly decreased. In addition, the weighted decay times of sIPSCs and mIPSCs were significantly increased in R/LM interneurons. Taken together, these findings illustrate the extensive redistribution and reorganization of inhibitory connections between interneurons that can take place in a malformed brain.