Reference of 55-22-1 , The common heterocyclic compound, 55-22-1, name is Isonicotinic acid, molecular formula is C6H5NO2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.
(A) 2-(4-Pyridinyl)benzoxazole A mixture of 2-aminophenol (10.9 g), isonicotinic acid (12.3 g) and polyphosphoric acid (250 g) is heated under a nitrogen atmosphere at 210 C. for 3 hours. The mixture is then cooled to 160 C. and slowly poured into 1 liter of water. The mixture is cooled by adding ice and neutralized with 50% sodium hydroxide solution yielding 16.2 g of crude product. Crystallization from hexane yields 14.8 g of the title compound, melting point 129-131 C.
The synthetic route of 55-22-1 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; E. R. Squibb & Sons, Inc.; US4169200; (1979); A;,
Pyridine – Wikipedia,
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