ChemInform Abstract: REAKTIONEN VON PYRIDINIUMSALZEN UND PYRIDINBASEN 5. MITT. SYNTHESE VON 4‐ALKOXY‐, 4‐ALKYLMERCAPTO‐ UND 4‐ALKYL‐PYRIDINEN

Abstract

Das Phenoxypyridin (III) läßt sich mit den Alkoholaten bzw. Mercaptiden (II) bei 110‐170°C (Reaktionsdauer 3‐20 Std.) zu den Alkoxy‐ und Alkylmercaptopyridinen (I) umsetzen.

Synthesis of 4-alkoxypyridines as intermediates for zwitterionic liquid crystals

“…12,18 In another modification, 4-chloropyridine (5) or 4-bromopyridine is reacted with excess propanol (6[3]), K2CO3 and catalytic amounts of Zn(NO3)2•6H2O at 75 o C for 24 hours giving 1 [3] in 84% yield. 30 In some earlier literature, N-(pyrid-4-yl)pyridinium hydrochloride 19 and 4phenoxypyridine 32,33 were reacted with RONa in excess alcohol to obtain some 1[n].…”

Synthetic applications of N–N linked heterocycles. Part 12. The preparation of 4-alkylthio- and 4-arylthio-pyridines by regiospecific attack of thioalkoxide lons on N-(4-oxopyridin-1-yl)pyridinium salts

“…methy1acetamido)pyridiniw-n iodide.13 Therefore pyridinium salts (5), (6), and ( 7), having R2 = H, and R3 = H, Me, and Ph, respectively, were treated with thiolate ions, and as can be seen from Table 1, intermediates ( 11) -( 13) were isolated, some in very good yield [e.g. (lla), (Ilk), and (13d)l.f This result appears to substantiate the reversibility of thiolate addition under the conditions described here.…”

“…N-(2-Methyl-4-oxopyridin-1 -yl)pyridinium tetrafluoroborate (6). 1-Aminopyridinium chloride (12 g, 0.092 mol), and 6-methyl-4-oxopyran-2-carboxylic acid (12.3 g, 0.083 mol) in concentrated HC1 (80 ml) were refluxed together in a 500-ml flask (considerable foaming) for 72 h. The dark product was treated with charcoal (2 g ) , filtered hot, evaporated to dryness and the residue heated with aqueous HBF, (35y0-; 20 g, 0.08 mol) and absolute EtOH (25 ml).…”

“…t Intermediates derived from salts (5),(6), and (7) all proved to be too unstable for microanalysis, but were identified from their i.r. and lH n.m.r.…”