Pyridine

Basics

• Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N
• It is structurally related to benzene, with one methine group (=CH−) replaced by a nitrogen atom
• It is a colorless, highly flammable, weakly alkaline, water-soluble liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless
• Older or impure samples can appear yellow.
• It is a basic industrial chemical feedstock

Synthesis

Chichibabin synthesis

Basics

• This process is carried out in a gas phase at 400–450 °C with a a transition metal salt such as cadmium(II) fluoride or manganese(II) fluoride, or cobalt and thallium compound catalyst

Inputs

• Acetaldehyde
• Formaldehyde
• Ammonia
• The catalyst

Process

• First, Acrolein is formed in a Knoevenagel condensation from the acetaldehyde and formaldehyde
• The acrolein is then condensed with acetaldehyde and ammonia to give Dihydropyridine
• This is then oxidized with a solid-state catalyst to pyridine.

Outputs

• The product consists of a mixture of pyridine, simple methylated pyridines (picolines and lutidines);

its composition depends on the catalyst used and can be adapted to the needs of the manufacturer via changing the catalyst accoordingly

Internal Links

• Pyridinium Chloride

External Links

• The Wikipedia Page on Pyridine