References benzoxazoles

Fio. 1. Bronsted plot for azoles reacting with methylating agents in quaternization reactions. Pyridine is the reference substrate. 1, 1-methylimidazole 2, 1-methylbenzimidazole 3, thiazole 4, 1-methylpyrazole 5, 2-methylindazole 6, benzo-thiazole 7, oxazole 8, 1-methylindazole 9, benzoxazole 10, 2,1-benzisothiazole 11, isothiazole 12, 2,1-benzisoxazole 13, isoxazole and 14, 1,2-benzisoxazole. 

Sections VI,A, B, D, and E give information about indazoles, oxazole, benzoxazole, isoxazole, benzisoxazoles, isothiazole, benziso-thiazoles, and benzothiazole. In addition, Sections II and VI,F,1 refer to quaternization reactions of isoxazole and benzisothiazoles, respectively. 

Gross and coworkers129 also studied the unimolecular dissociation of protonated acy-lanilines, viz. A-[2-(benzoyloxy)phenyl]benzamides formed via both fast-atom bombardment (FAB) and electrospray ionization (ESI). They found that cyclization occurs upon the loss of a molecule of benzoic acid, and that a similar process occurs for the molecular ion under El. This gas-phase reaction is analogous to a solution reaction leading to phenyl-benzoxazoles. The proposed cyclization process, for which concurrent mechanisms were proposed (Scheme 38 depicts only the displacement reaction route), was corroborated by accurate mass measurements, tandem mass spectrometric experiments with comparison with reference ions, isotopic labeling and theoretical calculations. 

As in CHEC-I <84CHEC-I(6)177>, the naming and numbering of oxazole and its derivatives follow the convention of Chemical Abstracts. The fully conjugated compounds are called oxazoles (1), benzoxazoles (2), oxazolium salts (3), and oxazole A -oxides (4). Hydroxy-substituted oxazoles exist in the oxo form, and there are five representatives the 2QH)-, 2(SH)-, 4(5//)-, 5(2//)-, and 5(4//)-oxazolones, (5)-(9) respectively. There are two mesoionic structures, the anhydro-4-hydroxy-oxazolium hydroxides (10) and the 5-hydroxy analogues (11), the latter of which are also referred to as the munchnones. Compound (12) is named 4,5-dihydrooxazole instead of A -oxazoline or 2-oxazoline, which is commonly used in the general literature. The other dihydrooxazoles include the less common 2,3- and 2,5-dihydrooxazoles, (13) and (14), respectively. The fully saturated compound... 

It should be noted that there is also a large body of literature on the photophysics of benzoxazole derivatives, which is outside of the scope of this review but clearly of relevance to those in the field. Leading references are provided for benzoxazole itself " and the widely studied oxazole yellow fluorescent dyes and their interactions with DNA strands. 

Yang P and Gu Y (2012), Synthesis of a novel benzoxazine-containing benzoxazole structure and its high performance thermoset , J Appl Polym Sci, 124, 2415-2422. Yoonessi M, Toghiani H, Wheeler R, Porcar L, Kline S and Pittman Jr C U (2008), Neutron scattering, electron microscopy and dynamic mechanical studies of carbon nanofiber/phenolic resin composites . Carbon, 46, 577-588, and references therein. Yosomiya R (1990), Adhesion and Bonding in Composites, New York, Marcel Dekker, l-A. 

A variety of chemical modifications have been made in rigid rod polymers such as including bulky side groups [102,103] and introducing a small fraction of a multifunctional monomer [104, 105]. The modified PBO referred to as polyfaryl ether benzoxazoles) was synthesized by using the nucleophilic aromatic displacement of an aryl halide with a phenoxide in polar aprotic solvents [106,107]. 

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