Synthesis and anti-arrhythmic activity of some piperidine-based 1,3-thiazole, 1,3,4-thiadiazole, and 1,3-thiazolo[2,3-c]-1,2,4-triazole derivatives

Cu(II)-Catalyzed C-N Coupling of (Hetero)aryl Halides and N-Nucleophiles Promoted by α-Benzoin Oxime

We first reported the new application of a translate metal chelating ligand α-benzoin oxime for improving Cu-catalyzed C-N coupling reactions. The system could catalyse coupling reactions of (hetero)aryl halides with a wide of nucleophiles (e.g., azoles, piperidine, pyrrolidine and amino acids) in moderate to excellent yields. The protocol allows rapid access to the most common scaffolds found in FDA-approved pharmaceuticals.

Synthesis of benzensulfonamides linked to quinazoline scaffolds as novel carbonic anhydrase inhibitors

Carbonic anhydrase (CA) inhibitory activities of newly synthesized quinazoline-linked benzensulfonamides 10-29, 31, 32, 35, 36, and 45-51 against human CA (hCA) isoforms I, II, IX, and XII were measured and compared to that of acetazolamide (AAZ) as a standard inhibitor. Potent selective inhibitory activity against hCA I was exerted by compounds 14, 15, 17, 19, 20, 21, 24, 25, 28, 29, 31, 35, 45, 47, 49, and 51 with inhibition constant (K_Is) values of 39.4-354.7 nM that were nearly equivalent or even greater than that of AAZ (K_I, 250.0 nM). Compounds 15, 20, 24, 28, 29, 45 and 47 proved to have inhibitory activities against hCA II with (K_Is, 0.73-16.5 nM) that were similar or improved to that of AAZ (K_I, 12.0 nM). Compounds 13-29, 31-32, and 45-51 displayed potent hCA IX inhibitory activities (K_Is, 1.6-32.2 nM) that were more effective than or nearly equal to AAZ (K_I, 25.0 nM). Compounds 14, 15, 20, 21, 26, 45, and 47 exerted potent hCA XII inhibitory activities (K_Is, 5.2-9.2 nM), indicating similar CAI activities as compared to that of AAZ (K_I, 5.7 nM).

3-Oxo-3-(piperidin-1-yl)propanenitrile

In the title compound, C₈H₁₂N₂O, the piperidine ring exhibits a chair conformation and its least-squares plane (all atoms) makes a dihedral angle of 32.88 (12)° with the propane­nitrile unit (r.m.s. deviation = 0.001 Å). In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains along [001].

(Z)-2-(5-Acetyl-4-methyl-3-phenyl-2,3-dihydro-1,3-thia-zol-2-yl-idene)-3-(3-methyl-1-benzofuran-2-yl)-3-oxo-propane-nitrile

In the title compound, C(24)H(18)N(2)O(3)S, the benzofuran ring system (r.m.s. deviation = 0.010 Å) forms dihedral angles of 83.13 (17) and 8.92 (14)° with the benzene and thia-zole rings, respectively. The dihedral angle between the benzene and thia-zole rings is 84.51 (19)°. The mol-ecular structure features an intra-molecular C-H⋯O hydrogen bond, which closes an S(6) ring. There are no inter-molecular hydrogen bonds observed in this structure.

Stereoselective synthesis and antiviral activity of (1E,2Z,3E)-1-(piperidin-1-yl)-1-(arylhydrazono)-2-[(benzoyl/benzothiazol-2-oyl)hydrazono]-4-(aryl(1))but-3-enes

The reaction of benzoyl hydrazine 1a or benzothiazole-2-carbohydrazide 1b with 2-oxo-N-arylpropanehydrazonoyl chlorides 2a-d yielded (1Z,2E)-2-[(benzoyl/benzothiazol-2-oyl)hydrazono]-N-(aryl)propanehydrazonoyl chlorides 3a-e. The reaction of 3a-c with sodium benzenesulphinate furnished sulphones 5a-c while the reaction of 5d, e with hydroxyl amine afforded hydroxomoyl derivatives 6a, b. The one-pot sterioselective reaction of N-(aryl)propanehydrazonoyl chlorides 3 with certain aromatic aldehydes in the presence of piperidine resulted in the formation of (1E,2Z,3E)-1-(piperidin-1-yl)-1-(arylhydrazono)-2-[(benzoyl/benzothiazol-2-oyl)hydrazono]-4-(aryl1)-but-3-enes 7a-g. X-ray analysis of piperidinyl amidrazone 7g showed a conversion of its geometrical structure with respect to that of compound 3 and confirmed the stereoselectivity of the latter reaction. The piperidinyl amidrazones 7a-g possessed a significant antiviral activity against herpes simplex viruses (HSV-1). Compound 7d reduced the number of viral plaques of herpes simplex type-1 (HSV-1) by 67%, with respect to the effect of reference drug Aphidicolin.

Synthesis of new 2-naphthyl ethers and their protective activities against DNA damage induced by bleomycin-iron

The reaction of 2-naphthaloxyacetic acid with thiosemicarbazide in the presence of phosphoryl chloride, followed by treatment with phenacylbromides, led to the formation of imidazo[2,1-b][1,3,4]thiadiazoles 3a-c. 2-(Naphthalen-3-yloxy)acetohydrazide 4 on treatment with ethyl 2-(2-arylhydrazono)-3-oxobutanoates (5a-c), 2-methoxymethylene)malononitrile, or ethyl 2-cyano-3,3-bis(methylthio)acrylate led to the formation of substituted pyrazoles 6-8. The reaction of the hydrazide 4 with hydrazonoyl chlorides 9a-c and 1,2,4,5-benzene tetracarboxylic-1,2:4,5-dianhydride produced bis-diazo compounds 10a-c and dimide 11 respectively. All new compounds were tested for their protective activity against DNA damage induced by bleomycin-iron complex. Compound 2 showed the greatest protection against DNA damage, thus diminishing chromogen formation between the damaged DNA and thiobarbituric acid.