Isoquinoline
isoquinoline
[¦ī·sə′kwin·ə‚lēn]Isoquinoline
colorless crystals with a faint odor of almonds. Melting point, 24.5°C, and boiling point, 243°C. Its structural formula is
Slightly soluble in cold water, isoquinoline dissolves readily in organic solvents. It is present in low concentration in coal tar, from which it is separated with quinoline. Isoquinoline is a stronger base than quinoline. The most important method of preparing isoquinoline and its derivatives is by cyclodehydration of /3-phenylethylamides of acids C6H5CH2CH2NHCOR (the Bischler-Napieralski reaction) followed by dehydrogenation of the resultant 3, 4-dihydroisoquinolines. The isoquinoline nucleus is present in a number of important alkaloids, such as papaverine, morphine, codeine, and curarine.