Isoquinoline

Isoquinoline is an organic compound with the formula C9H7N. It is a heterocyclic aromatic organic compound similar to benzene and pyridine, and is often used as a building block for more complex chemical compounds, including many found in natural products and pharmaceuticals.

Structure and reactivity

Isoquinoline is a colorless hygroscopic liquid at room temperature with a penetrating, unpleasant odor. The structure of isoquinoline is virtually identical to that of quinoline, but the nitrogen atom is in position 2 of the ring, not position 1. Isoquinoline is a weak base, with a pKa of 5.14. It forms salts with acids, which are usually solid and water-soluble.

Synthesis

Isoquinoline can be synthesized in a number of ways, but the most common method is the Pomeranz-Fritsch reaction, which involves the condensation of benzaldehyde with a nitrogen-containing compound.

Applications

Isoquinoline is used in the manufacture of a number of pharmaceuticals, including papaverine and laudanosine. It is also used in the production of dyes and plastics, and as a corrosion inhibitor for metals.

Health effects

Exposure to isoquinoline can cause eye and skin irritation, and prolonged exposure can lead to central nervous system depression. It is also a potential occupational carcinogen.

See also

• Quinoline
• Pomeranz-Fritsch reaction
• Benzene
• Pyridine