Acenaphthenes

Naphthalimides are prepared from naphthaUc anhydride obtained from naphthalene-1,8-dicarboxyhc acid, ie, the oxidation product of acenaphthene or its derivatives, by reaction with amines. They are utilized for synthetic fibers such as polyesters. 

This article deals mainly with naphthalene [91-20-3]. The hydrogenated naphthalenes, the alkylnaphthalenes (particularly methyl- and isopropylnaphthalenes), and acenaphthene also are discussed (see also Naphthalenederivatives). 

Acenaphthene. Acenaphthene [83-32-9] is a hydrocarbon, present in high temperature coal tar (6). Acenaphthene may be halogenated,... 

The anhydride can be made by the Hquid-phase oxidation of acenaphthene [83-32-9] with chromic acid in aqueous sulfuric acid or acetic acid (93). A postoxidation of the cmde oxidation product with hydrogen peroxide or an alkaU hypochlorite is advantageous (94). An alternative Hquid-phase oxidation process involves the reaction of acenaphthene, molten or in alkanoic acid solvent, with oxygen or acid at ca 70—200°C in the presence of Mn resinate or stearate or Co or Mn salts and a bromide. Addition of an aHphatic anhydride accelerates the oxidation (95). 

The anhydride of 1,8-naphthalenedicarboxyHc acid is obtained in ca 95—116 wt % yield by the vapor-phase air-oxidation of acenaphthene at ca 330—450°C, using unsupported or supported vanadium oxide catalysts, with or without modifiers (96). 

For example, 5,6-acenaphthenedicarboximide (44) can be prepared in 84% yield by the reaction of acenaphthene with excess sodium cyanate in anhydrous HF (78). The intermediate can be oxidized to the tetracarboxyhc acid. 

Sources of Raw Materials. Coal tar results from the pyrolysis of coal (qv) and is obtained chiefly as a by-product in the manufacture of coke for the steel industry (see Coal, carbonization). Products recovered from the fractional distillation of coal tar have been the traditional organic raw material for the dye industry. Among the most important are ben2ene (qv), toluene (qv), xylene naphthalene (qv), anthracene, acenaphthene, pyrene, pyridine (qv), carba2ole, phenol (qv), and cresol (see also Alkylphenols Anthraquinone Xylenes and ethylbenzenes). 

Acenaphthene [83-32-9] M 154.2, m 94.0 . Crystd from EtOH. Purified by chromatography from CCI4 on alumina with benzene as eluent [McLaughlin and Zainal J Chem Soc 2485 I960]. 

Acenaphthene Acetaldehyde Acetic acid Acetic anhydride Acetone... 

Preferential elimination of hydrogen fluonde from vicinal halofluoro compounds occurs also in the cyclohexane series [55 56, 57], acenaphthene series [55], and benzodihydrofuran series [59 60] Here, the strength of the base and the stereochemistry play important roles... 

Accracopalinsaure,/. accracopalim c acid, Accracopalsaure, /. accracopalic acid. Aceanthrenchinon, n. aceanthrenequinone. Acenaphten, n. acenaphthene. -chinon, n. 

Naphthalene, acenaphthane, acenaphthene, fluorene, phenan-threne, anthracene, fluoranthene, pyrene, benzanthracene, benzophenanthrene, and benzpyrene... 

---