Novel 1,4-dihydropyridine calcium antagonists. I. Synthesis and hypotensive activity of 4-(substituted pyridyl)-1,4-dihydropyridine derivatives.

Synthesis and spectroscopy of anionic tridentate benzimidazole-pyridine carboxylate and tetrazolate chromophore ligands

“…We note that mono-oxidation of bis-methanol-pyridines to carboxaldehyde can also be achieved with MnO 2 as oxidant [34]. The known 2,6-disubsituted pyridines P3 [35][36][37] and P4 [36][37][38], which we planned to use in the synthesis of tetrazoles, were prepared from P1 (we described its multi-gram synthesis before [12]) by conversion of the carboxaldehyde into the carbonitrile P3 with NH 2 OHÁHCl in DMSO [39], and by oxidation of the pyridine-2-methanol to the carboxaldehyde P4 with SeO 2 (Scheme 3).…”

“…The product shows one spot on TLC (silica; ethyl acetate). It is soluble in organic solvents, and it remains soluble even after long storage as a solid (in contrast to the nonsubstituted analog P1 P3: For alternative syntheses, see [35][36][37]. The reaction was performed under nitrogen.…”

“…Pale yellow solid: 446 mg (3.32 mmol; 61%; C 7 H 6 N 2 O; MW 134.14). It can be checked for the presence of DMSO by recording 1 P4: For alternative syntheses, see [36][37][38]. The reaction was performed under nitrogen.…”

Chiral amine–imine ligands based on trans-2,5-disubstituted pyrrolidines and their application in the palladium-catalyzed allylic alkylation

“…Pyridine and methanol were dried over freshly activated 4 Å molecular sieves before use. Compounds 11, 32 12, 33 18-20, 43 21, 44 25, 45 26, 46 and 32-34 16 were prepared according to literature procedures. All other solvents and reagents were purchased from commercial sources and used as received.…”

“…2-Picoline 16 and 2,6-dimethylpyridine 17 were oxidized (mCPBA) to afford the corresponding N-oxides 18 and 19, respectively. 43 The N-oxides were then nitrated at the 4-position to give 20 43 and 21. 44 Subsequent transformation of 20 into an acetate by rearrangement in acetic anhydride at 100°C 45 yielded 22 in 90% yield (Scheme 4).…”