Isoquinolines

Isoquinoline

Names
Preferred IUPAC name Isoquinoline
Other names Benzo[c]pyridine 2-benzanine
Identifiers
CAS Number	119-65-3 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:16092 N
ChemSpider	8098 Y
DrugBank	DB04329 N
ECHA InfoCard	100.003.947
EC Number	204-341-8
PubChem CID	8405
UNII	JGX76Y85M6 N
InChI InChI=1S/C9H7N/c1-2-4-9-7-10-6-5-8(9)3-1/h1-7H Y Key: AWJUIBRHMBBTKR-UHFFFAOYSA-N Y InChI=1/C9H7N/c1-2-4-9-7-10-6-5-8(9)3-1/h1-7H Key: AWJUIBRHMBBTKR-UHFFFAOYAX
SMILES C1(C=NC=C2)=C2C=CC=C1
Properties
Chemical formula	C9H7N
Molar mass	129.16 g·mol−1
Appearance	yellowish oily liquid, hygroscopic platelets when solid
Density	1.099 g/cm3
Melting point	26 to 28 °C (79 to 82 °F; 299 to 301 K)
Boiling point	242 °C (468 °F; 515 K)
Acidity (pKa)	pKBH+=5.14
Magnetic susceptibility (χ)	-83.9·10−6 cm3/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Isoquinoline is a heterocyclic aromatic organic compound. It is a structural isomer of quinoline. Isoquinoline and quinoline are benzopyridines, which are composed of a benzene ring fused to a pyridine ring. In a broader sense, the term isoquinoline is used to make reference to isoquinoline derivatives. 1-Benzylisoquinoline is the structural backbone in naturally occurring alkaloids including papaverine. The isoquinoline ring in these natural compound derives from the aromatic amino acid tyrosine.

Isoquinoline is a colorless hygroscopic liquid at room temperature with a penetrating, unpleasant odor. Impure samples can appear brownish, as is typical for nitrogen heterocycles. It crystallizes platelets that have a low solubility in water but dissolve well in ethanol, acetone, diethyl ether, carbon disulfide, and other common organic solvents. It is also soluble in dilute acids as the protonated derivative.

Being an analog of pyridine, isoquinoline is a weak base, with a pK_a of 5.14. It protonates to form salts upon treatment with strong acids, such as HCl. It forms adducts with Lewis acids, such as BF₃.