Carboxymethyl reactions+toluenes

The carboxymethyl-dextran derivative may be used to couple amine-containing molecules by the carbodiimide reaction. Heindel et al. (1994) prepared the lactone derivative of carboxymethyl-dextran by refluxing for 5 hours in toluene or other anhydrous solvents. The lactone derivative is highly reactive toward amine-containing molecules, thus creating a preactivated polymer for conjugation purposes. 

Heating a mixture of 2-(carboxymethyl)benzoic acids and 3-amino-propanol in o-dichlorobenzene in the presence of p-toluenesulfonic acid yielded 2,3,4,6-tetrahydro[l,3]oxazino[3,2-b]isoquinolin-6-ones (78BEP 866987, 78GEP2756067 79CPB2372). Similar reaction between o-benzoylphenylacetic acid and 3-aminopropanol in toluene resulted in 11 b-phenyl-2,3,4,6,7,116-hexahydro[l,3]oxazino[2,3-a]isoquinolin-6-one (71MI1). Reaction of 2-(2-bromoethyl)benzaldehyde and 3-aminopropanol in ethanol led to 2,3,4,6,7,llb-hexahydro[l,3]oxazino[2,3-a]isoquinoline (61AP645). 

A mixture of dl-2-[4-(2 -carboxymethyl-4 -methylphenoxy)phenyl]propionic acid (15.3 g) and polyphosphoric acid (92 g) was heated with stirring at 110-120°C for 2 hours. To the reaction mixture was added water and the resulting mixture was extracted with chloroform. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated. The residue was chromatographed on silica gel (75 g) using chloroform as an eluent to give a crude product, which was recrystallized from toluene to give the dl-2-(8-methyl-10,ll-dihydro-ll-oxodibenz[b,f]oxepin-2-yl)propionic acid (9.4 g, 65.3%), m.p. 128-129°C. 

Kooyman et a/.232-234 showed that no direct reaction between the arene and Mn(IIl) occurred in the manganic acetate oxidation of benzene, chlorobenzene, and toluene in acetic acid. Products were satisfactorily explained by the participation of carboxymethyl radicals as intermediates analogous to those formed in the manganic acetate oxidation of olefins [see Section II.B.3.a]. Substituted... 

For the reaction of Mn " acetate with substituted toluenes in acetic acid (130 °C) under anaerobic conditions, an analogous correlation between log( iy i ) and ff exists (Heiba et al. [Ha] Figure 2). Here, however, the reaction is not the direct interaction of Mn" with the arene but the reaction of carboxymethyl radicals, generated from Mn " acetate, with the a-hydrogen atoms of the alkyl group on the arene (eqs. (22) and (23)). 

Alkyl radicals can be obtained by abstraction of a hydrogen atom from an alkyl group by another radical. This method was utilized for the generation of benzyl radicals from toluene with tert-butoxy radical obtained on heating di-ier -butyl peroxide. Benzoyl and carboxymethyl radicals have also been obtained by this method. The reaction gives rise to a complex mixture of products and therefore is of rather limited use. 

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