4815-43-4

In the course of search for new therapeutic agents against epilepsy new inhibitors for the kainate receptor subtypes GluR5 and GluR6 were synthesized. We were able to synthesize new substituted thieno[2,3-d]pyrimidines 3a,b, 4a,b, 5a,b as well as thiophene-3-carboxamides 2a-d and a multitude of substituted 4-methyl-5-phenylthiophene-3-carboxylic acids. All compounds described herein were tested for their antagonistic effect towards the kainate receptor subtypes GluR5 and GluR6. The highest activity was observed for ethyl 2-amino-4-methyl-5-phenylthiophene-3-carboxylate 1c with an IC50 = 0.75 μM at the GluR6 receptor.

2-Amino-3-aroylthiophenes are agonist allosteric enhancers (AE) at the A1, adenosine receptor (A1AR). Here we report the syntheses of three kinds of novel 2-aminothiophenes and assays of their AE activity at the human A1AR (hA1AR), namely, (1) 2-amino-4,5-diphenylthiophene-3-carboxylates, 3a-h, (2) 2-amino-3-benzoyl-4,5-diphenylthiophenes, 7a-p, and (3) 2-amino-5-bromo-3-benzoyl-4-phenylthiophenes, 10a-h. An in vitro assay employing the A1AR agonist [125I]ABA and membranes from CHO-K1 cells stably expressing the hA1AR measured an index of AE activity, the ability of a candidate AE to stabilize the agonist-A1AR-G protein ternary complex, scored as the percentage of ternary complex remaining after 10 min of dissociation initiated by CPX and GTPγS. The AE activity score of 2-amino-4,5-dimethyl-3-(3-trifluoromethylbenzoyl)thiophene (PD 81,723), which was 19%, served as a standard for comparison. Two 3-carboxythiophene 3-trifluoromethylbenzyl esters, 3d (49%) and 3f (63%), had substantial AE activity. The 3-(1-naphthoyl) substituent of 7e (52%) also supported AE activity. Compounds in series 3 tended to be more potent, 10a and 10c having scores of 91 and 80%, respectively. The activity of 2-amino-5-bromo-3-ethoxycarbonyl-4-(3-nitrophenyl)thiophene, 10h (26%), is an exception to the rule that a 3-ethoxycarbonyl substituent cannot support AE activity.