Regiospecific introduction of alkyl groups into 4-position of pyridine novel synthesis of 4-substituted pyridines

✍ Scribed by Kin-ya Akiba; Hideto Matsuoka; Makoto Wada

• Book ID: 104234406
• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 245 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)82074-8

✦ Synopsis

Regiospecific synthesis of 4-substituted pyridines is attained y& alkylation of diisopropyl 1-ethoxycarbonyl-1, 4-dihydropyridine-4-phosphonate followed by treatment with butyllithium. The phosphonate is prepared directly from pyridine in one pot. Considerable efforts have been made to introduce substituents directly to pyridine and Grignard reagents and organolithiums are shown to add at 2-position to afford a-substituted pyridines after air oxidation. 1) S-Substituted pyridines are also prepared by alkylation of 1, 2-dihydropyridine generated in situ from pyridine and lithium aluminum -hydride. and phenI:cadmiums4) Acylpyridinium salts are attacked mainly at 2-position by Grignard reagents 3, 4)