Phthalic anhydrides irradiation

Jang and McDow (1997) studied the photodegradation of benzo[a]anthracene in the presence of three common constituents of atmospheric aerosols reported to accelerate benzo [a] anthracene, namely 9,10-anthroquinone, 9-xanthone, and vanillin. The photo-degradation experiments were conducted using a photochemical reactor equipped with a 450-W medium pressure mercury arc lamp and a water bath to maintain the solution temperature at 16 °C. The concentration of benzo [a] anthracene and co-solutes was 10" M. Irradiation experiments were conducted in toluene, benzene, and benzene-c/e- Products identified by GC/MS, FTIR, and NMR included benzo[a]an-thracene-7,12-dione, phthalic acid, phthalic anhydride, 1,2-benzenedicarboxaldehyde, naphtha-lene-2,3-dicarboxylic acid/anhydride, 7,12-dihydrobenzo[a]anthracene, 10-benzyl-10-hydroan-thracen-9-one, benzyl alcohol, and 1,2-diphenylethanol. 

The photodecomposition of phthalic anhydride has received detailed attention132 and 8 has been shown to be a definite but minor product with irradiation at 308 nm the major path involves CO and C02 ejection to benzyne. Indeed, the use of low temperature photochemical methods to provide 8 has much appeal as equation 18 and the sequences of Scheme 11 attest. The deazetation133 of 84 probably proceeds via carbene 85 which under-... 

Keywords maleic anhydride, phthalic anhydride, primary amine, TaCl5-silica gel, microwave irradiation, /V-alkylimide, /V-arylimide... 

Phthalic anhydride 3 (0.36 g, 2.4 mmol) and benzylamine (0.27 mL, 2.4 mmol) were adsorbed on activated silica gel (100-200 mesh, dried overnight at 100 °C) and stirred at room temperature for 1 h under inert atmosphere. To this was added TaCls-Si02 (0.37 g, 10 mol%) and admixed thoroughly and irradiated in a microwave oven (448 W) for 5 min. The mixture was cooled to room temperature, charged on a small silica pad and eluted with CH2CI2 (30 mL). Removal of volatiles furnished (V-benzyl phthalimide 4 (0.53 g, 92%). 

Keywords phthalic anhydride, benzylamine, microwave irradiation, phthalimide... 

In a typical reaction, 9.15 mmol of benzylamine 2 (1 mL) and 9.15 mmol of phthalic anhydride 1 (1.35 g) were introduced into a Pyrex flask, and then submitted to microwave irradiation under conditions of time and temperature as indicated. At the end of the irradiation, the reaction mixture was cooled to room temperature. The crude solid was recrystallized from ethanol to afford 1.95 g (8.23 mmol, 90%) of pure 3 as white crystals. 

Keywords urea, phthalic anhydride, microwave irradiation, metallophthalocya-nine... 

In order to eliminate the influence of temperature on the rate of a chemical reaction, a reaction mixture of phthalic anhydride with amino acids was placed in a block of ice and then irradiated under microwave conditions. Ice was used to cool the reaction mixture because opposite to water it is transparent to microwaves (e 3.2, c" 0.0029 at 25°C for 2.45 GHz) [26]. The reaction product was formed after 3 min. of irradiation while under conventional conditions the reaction was conducted in a boiling toluene solution for 1.5 h. However, since in such a case microwaves interact directly with the reaction mixture and temperature was not monitored during the experiments, it was stated that the increase of the reaction rate is not only due to thermal effects [27]. 

Bogdal et al. have obtained unsaturated polyesters in polyaddition reactions of alkylene oxides such as epichlorohydrin and acid anhydrides (maleic and phthalic anhydrides) in the presence of lithium chloride as catalyst under microwave irradiation conditions (Scheme 14.22) [51, 52]. In the standard procedure, a mixture of 0.10 mol phthalic anhydride and 0.10 mol maleic anhydride with 0.010 mol ethylene glycol, 0.20 mol epichlorohydrin, lithium chloride (0.1% w/w) was placed in a... 

Polycondensation of acid anhydrides (maleic and phthalic anhydrides) with diols (e.g. ethylene glycol) under microwave irradiation conditions has also been described for synthesis of unsaturated polyesters [52]. In addition to the previous procedure, the reaction temperature was increased to 200 °C and a Dean-Stark trap was used to remove water from the reaction mixture (Scheme 14.23). It was found that reaction times for the microwave and conventional procedures were comparable and depended on the rate of removal of water from the reaction system. 

A one-pot four-component reaction of aldehyde, phthalic anhydride, hydrazini-um hydroxide, and dimedone nnder nltrasonic irradiation in IL [BMImJBr has been described, which generated various 2 H-indazolo[2,l-b]phthalazinetriones in good yields under neutral and catalyst-free conditions [114] (Scheme 7.12). 

Synthesis of Xcaiboxyalkyl maleimide and phthalimides is carried out under microwave irradiations to give nearly 95 % yield. The reactants taken are maleie and phthalic anhydrides and are condensed with amino acids for 2-3 min to give the products [57], The reactions are given in Scheme 11.15. 

Phthalaldehydic acid dissolved in benzene, dried by distilling off a portion of the solvent, N-bromosuccinimide, a little benzoyl peroxide, and CCI4 added, then irradiated with a 500 w. lamp and refluxed 1 hr. phthalic anhydride. Y 95%. F. e. s. E. Maekawa and Y. Sumimoto, Bull. Chem. Soc. Japan 33, 941 (1960). 

To understand the primary photochemistry of 6F-PIs in air, Hoyle et al. [I72-I74] used V-phenylphthalimide as a model compound, since this model probably reflects the structural units in 6F-PIs where conjugation between the diimide groups is prevented by the C(CF3)3 bridge. Upon irradiation with a Pyrex filtered medium pressure mercury lamp, this model in an air-saturated acetonitrile solution rapidly decomposes to form phthalic anhydride (quantum yield major product, phthalimide (0 = 2X and a trace amount of nitrobenzene (this originates probably from... 

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