4- -1 - 5-phenyl-1,3,4-oxadiazol

Via an analogous way, 3-amino-5-phenyl-oxadiazole has been obtained from N-benzoyl-O-ethyl isourea 25f) ... 

In 1961, the catal5dic reduction of 3.5-diphenyl-, 3-phenyl-5-methyl and 3-methyl-S-phenyl oxadiazole has been reported by Palazzo [61b) who studied the influence of various reaction conditions such as the temperature, the solvent and the nature of the catalyst Pd on C, Adams-Pt and Raney-Ni. The opening of the N—O linkage occurs in each experiment. In the reduction of diphenyloxadiazole with Pd on C under 3 atm. one equivalent of hydrogen is absorbed and benzamidine benzoate is isolated in high yield. A small amount of benzoyl benzamidine is also formed ... 

The reduction of 3-phenyl-5-methyl-oxadiazole with Pd on carbon, under 3 atm., yields 2,4-diphenyl-l,5-diacetyl dimethylenetriamine while 2,4-dimethyl-l,5-dibenzoyl dimethylenetriamine is formed from 3-methyl-5-phenyl oxadiazole. 

Methyloxadiazole and HgClg yield a complex XLIV. S-Phenyl-oxadiazole and HgCl gives directly the substituted derivative XLV. These mercurated compounds, on treatment with a halogen, yield the desired 5-halogeno-oxadiazoles 25a). 

However, hydrolysis of the oxime of 3-benzoyl-5-phenyl oxadiazole leads to benzoyl cyanamide (76). 

Cyclohexanone (9.8g, lOOmmol) and benzoyl azide (1.47g, lOmmol) dissolved in acetonitrile (100 mL) are irradiated according to procedure A for 6h. After evaporating the solvent and the excess of cyclohexanone, methanol was added and the products were separated by column chromatography (silica gel hexane/ethyl acetate 8 2). 0.98 g (45%) of the cycloadduct is obtained as oil as well as 0.19 g (12%) of the cycloadduct of benzoyl nitrene towards the solvent (2-methyl-5-phenyl-oxadiazol) and 0.6 g (40 %) phenyl-iV-methylcarbamate. 

Bis[5 -[3"-(p-aminophenoxy)-phenyl]-oxadiazol-2-yl]benzene 4,4 -Bis-(p-aminophenoxy)diphenyl-1,3,4-thiadiazole 3-(3-aminophenyl)-5-[3 -(4-aminophenoxy)phenyl]-1,2,4-triazole 3-(3-aminophenyl)-5-[3 -(4-aminophenylsulfonyl)phenyl]-1,2,4-triazole... 

N N 3-( p-Bromophenyl)-4-methyl- 1,2,5-oxadiazole 2-oxide 3-(p-bromo-phenyl)-4-methyl-l,2,5-oxadiazole 5-oxide 3,4-diphenyl-l,2,5-oxadiazole... 

Isoxazoles unsubstituted in the 3-position react with hydroxide or ethoxide ions to give )3-keto nitriles (243) -> (244). This reaction involves nucleophilic attack at the 3-CH group. 1,2-Benzisoxazoles unsubstituted in the 3-position similarly readily give salicylyl nitriles (67AHC(8)277), and 5-phenyl-l,3,4-oxadiazole (245) is rapidly converted in alkaline solution into benzoylcyanamide (246) (61CI(L)292). A similar cleavage is known for 3-unsubstituted pyrazoles and indazoles the latter yield o-cyanoanilines. 

Phenylisothiazole is nitrated predominantly in the meta position of the phenyl group, whereas 4-phenylisothiazole is nitrated ortho and para in the phenyl group <72AHC(14)1). Nitration of 3-phenyl-l,2,4-oxadiazole gives a mixture of m- and p-nitrophenyl derivatives <6301196). 

Methyl groups on C-linked phenyl attached to oxazoles, isoxazoles and oxadiazoles react with benzylidineaniline to give stilbene derivatives (Scheme 51) <78AHC(23)l7l). 

Oxadiazole, 5-ethyl-3-phenyl-dipole moment, 6, 379 (77JOC1555)... 

Oxadiazole, 2-amino-5-phenyl-mass spectra, 6, 429 methylation, 6, 431... 

Oxadiazole, 2-phenyl-melting point, 6, 430 molecular diagrams, 6, 428 reactions... 

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