Naphthalenes carbonylation

In addition to benzene and naphthalene derivatives, heteroaromatic compounds such as ferrocene[232, furan, thiophene, selenophene[233,234], and cyclobutadiene iron carbonyl complexpSS] react with alkenes to give vinyl heterocydes. The ease of the reaction of styrene with sub.stituted benzenes to give stilbene derivatives 260 increases in the order benzene < naphthalene < ferrocene < furan. The effect of substituents in this reaction is similar to that in the electrophilic aromatic substitution reactions[236]. 

The cross-conjugated system of two a,P-unsaturated carbonyl groups of both 1,2- and 1,4-quinones occurs in many polynuclear hydrocarbons, eg, 1,2-naphthoquinone [524-42-5] (8) and 1,4-naphthalenedione [130-15-4] (1,4-naphthoquinone) (9) (see Fig. 1). The carbonyl groups may be located in different rings, but occupy positions corresponding to the 1,2- or 1,4-orientation of monocyclic quinones, eg, in naphthalenes such as 2,6-naphthoquinone... 

The amplitude of the frontier orbitals determines the selectivity. The most reactive atom in a molecule has the largest amplitude of the frontier orbitals. The frontier orbitals overlap each other to the greatest extent at the sites with the largest amphtudes. Reactions occur on the atoms in the electron donors and acceptors, where the HOMO and LUMO amplitudes are largest, respectively. Electrophiles prefer the a position of naphthalene, an electron donor, with the larger HOMO amplitude (Scheme 21). Nucleophiles attack the carbons of the carbonyl groups, an electron acceptor, with the larger LUMO amplitude (Scheme 7). 

The formation of the naphthalene (73) from the bis-ylide (72) and diethyl ketomalonate involves an unusual olefin synthesis on the carbonyl of an ester group. The methylene-pyrans (75) were formed when the diethyl malonates (74) were refluxed with j3-keto-ylides in xylene or decalin. Possible intermediates are the ketens (76) and the allenes (77). Addition of ylide to the allenes gives the betaines (78) which form methylene-pyrans either directly or via acetylenes as shown. 

Naphtha (petroleum), see Petroleum ether Naphtha, varnish makers and painters, 50° flash Naphtha, varnish makers and painters, high flash Naphtha, varnish makers and painters, regular Naphthalene 2-Naphthol 1 -Naphthylamine Natural gas Nickel carbonyl Nicotine... 

Morpholine Naphtha (coal tar) Naphthalene (5-Naphthylamine Nickel carbonyl Nickel metal ST CT CT 1... 

Condensation of benzotriazole with 2-carboxybenzaldehyde gives 3-(benzotriazol-l-yl)phthalide 795 (Scheme 127). The anion derived from phthalide 795 adds to the ft-carbon atom of a,( -unsaturated carbonyl compounds E to produce anion 796 that by intramolecular nucleophilic attack on the phthalide carbonyl group is converted to anion 797. Spontaneous expulsion of benzotriazole from molecules 797 followed by aromatization leads to 1,4-dihydroxy-naphthalenes 798 <1997SC3951>. 

The benzanthrone system is susceptible to both electrophilic and nucleophilic attack. The most reactive sites towards electrophiles are the 3- and 9-positions, which can be compared with the 4,4 -positions in biphenyl. The 9-position is somewhat deactivated by the carbonyl group, however. Thus, for example, monobromination takes place at the 3-position and further substitution gives 3,9-dibromobenzanthrone. Nitration and benzoylation similarly give rise to the 3-substituted product. The 3-position is in fact peri-hindered (compare naphthalene) so that sulphonation yields the 9-sulphonic acid. Electron withdrawal by the carbonyl group activates the 4- and 6-positions towards nucleophilic attack for example, hydroxylation occurs at these sites. 

The solvent process involves treating phthalonitrile with any one of a number of copper salts in the presence of a solvent at 120 to 220°C [10]. Copper(I)chloride is most important. The list of suitable solvents is headed by those with a boiling point above 180°C, such as trichlorobenzene, nitrobenzene, naphthalene, and kerosene. A metallic catalyst such as molybdenum oxide or ammonium molybdate may be added to enhance the yield, to shorten the reaction time, and to reduce the necessary temperature. Other suitable catalysts are carbonyl compounds of molybdenum, titanium, or iron. The process may be accelerated by adding ammonia, urea, or tertiary organic bases such as pyridine or quinoline. As a result of improved temperature maintenance and better reaction control, the solvent method affords yields of 95% and more, even on a commercial scale. There is a certain disadvantage to the fact that the solvent reaction requires considerably more time than dry methods. 

Quinizarin.—1 4-dihydroxyanthraquinone is of no use as a dye it has been found, as a general rule, that only those polyhydroxyquinones of the anthracene and naphthalene series (naphthazarin) which have their adjacent OH-groups in positions adjoining the carbonyl group are capable of forming colour lakes. 

SOCl2 (208 g, 1.75 mol) is added in one portion to a refluxing solution of TEBA-Cl (0.27 g, l. 2 mmol) and the acid (0.826 mol) in Cl(CH2)2Cl (l. 5 l). The solution is refluxed for a further period of time, and then filtered hot and evaporated to yield the acid chloride, which is purified, if necessary, by chromatography from silica [e.g. trans-cyclohexane-1,4-dicarbonyl chloride (30 min), 96% naphthalene-2,6-dicarbonyl chloride (12 h), 94% biphenyl-4-carbonyl chloride (25 min), 60% biphenyl-4,4 -dicarbonylchlo-ride (16 h), 90%]. 

In the pioneering papers of Wawzonek et al. [18, 214] it was demonstrated that CO2 can be added to cathodicaUy reduced hydrocarbons to yield dihydrodi-carbonylates. Examples of this kind of reaction include naphthalene [215-220], anthracene [18], 9,10-diphenylanthracene [18], phenanthrene [215, 216], butadiene [217-220], stilbene [18], and diphenyl... 

Sodium naphthalene etching or Tetra Etch for PTFE improves the surface roughness and creates unsaturated bonds, carbonyl and carboxyl groups. 

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