Pyridine 2-benzoylamino

The N-silylated enol acetate 1523 is cyclized by TMSOTf 20 in CHCI3, in 95% yield, giving the oxazole 1524 [57]. The dimeric derivative 1525 affords the 2,2 -bis-oxazole 1526 in 46% yield [57]. 2-Benzoylamino-3-chloropyridine 1527 is cyclized by polyphosphoric acid trimethylsilyl ester (PPSE) 195 on heating for 15 h in boiling 1,2-dichlorobenzene to give 40-60% 2-phenyloxazolo[5,4-f)]pyridine 1528 [58] (Scheme 9.34). 

Benzoylamino-3-dimethylaminopropenoate reacts with methyl 2-pyridylacetate or 2-cyanomethylpyridine to give derivatives of the pyrido [l,2-fl]pyridine system. Alternatively, this ring system is also formed with ethyl A-methoxythiocarbonylglycine and TOF (Scheme 54) (94JHC125). 

Condensation of benzaldehyde with 2-amino-3-cyano- or -ethoxycar-bonylpyrazolo [ 1,5-a]pyridines gave the corresponding 2-benzylideno derivatives.66 A benzoylamino compound (265) was converted to the urea derivative 266.232... 

A different route to pyrones is the preparative electrochemical oxidation of enamines in acetonitrile in the presence of tetraethylammonium perchlorate (88MI2) (Scheme 46). The synthesis of 2-pyrone derivatives has been carried out by reaction of /3-dicarbonyl compounds with methyl-a-benzoylamino-/3-dimethylaminoacrylate (96JHC751). Thiapyran derivatives can be obtained by interaction of enamines based on (/3-amino-a-cyanoacryloylmethyl)pyridinium chloride derivatives with carbon disulfide (95M711).The synthesis of pyridine derivatives based on analogous enamines has been described as well (95M711). 

The 8-oxo-7-phenylacetylamino-5-thia-l-aza-bicyclo[4.2.0]oct-l-ene-2-carboxylic acid benzhydryl ester is reacted with phosphorus pentachloride/pyridine reagent in methylene dichloride, and the reaction mixture is thereafter cooled to -35°C and treated with methanol to produce hydrochloride of 7-amino-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester. This hydrochloride is reacted with 4-(3-aminothiophen-2-yl)-5-oxohex-3-enoic acid 3-methylbut-2-enyl ester. Then 7-[2-(2-benzoylamino-thiazol-5-yl)(3-tert-butyl-4,4-dimethylpent-2-enoxycarbonyl)-pent-2-enoylamino]-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid synthesized is reacted with aluminum chloride in anisole and diluted hydrochloric acid and then with dimethylmalonate to give 5-thia-l-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, 7-(((2Z)-2-(2-amino-4-thiazolyl)-4-carboxy-l-oxo-2-butenyl)amino)-8-oxo-, (6R,7R)- (Ceftibuten). 

On oxidation with O2 catalyzed by a Co(II) complex of 6,6 -bis(benzoylamino)-2,2 -bipyridine (233) in toluene containing an appropriate base such as pyridine (20 °C, 24 h), a quantitative conversion of 23 to 74 was observed. In addition, the durability of this complex as an oxygenation catalyst is much higher than that of 229 [Co(salen)]. Furthermore, the catalytic activity of 233 can be restored by heating it to 200 °C under reduced pressure because of its high thermal stability . ... 

The incorporation of a 3-carboxamidoxime group into the newly formed pyrimidine part of the pyrido[2,3-r(]pyrirnidine furnishes a 3-oxide function. Thus, 2-(benzoylamino)pyridine-3-carboxamidoxime (10) cyclizes in concentrated sulfuric or phosphoric acid to give 2-phenylpyrido[2,3-J]pyrimidin-4-amine 3-oxide (11).13... 

A mixture of 2-(benzoylamino)pyridine-3-carboxamidoxime (10 0.5 g, 2 mmol) and coned H2S04 (2 mL) was heated at 75-80 °C for 95 min until a clear solution was obtained. The cooled mixture was poured onto ice (7 g), the solid was 11 Itered (20 mg of BzOIl), and the filtrate was neutralized under cooling with coned NH4OH (pH 5-6) and left in ice. The separated product was crystallized (MeOH) to give the title compound yield 0.31 g (67%) tnp 214-215, C. 

Amino-l,2-dihydroacronycine (40 ) could be easily converted into variously substituted amines and amides. Treatment of 40 with formaldehyde and sodium borohydride afforded 2-dimethylamino-l,2-dihydroacronycine (42). Both aliphatic and aromatic amides were obtained from 4 upon treatment with acid anhydrides in pyridine. This latter reaction is exemplified by the preparation of 2-acetylamino-l,2-dihydroacronycine (43J and 2-benzoylamino-l,2-dihydroacronycine (44) using acetic anhydride and benzoic anhydride, respectively (53). 

When the racemic ornithine (Scheme 12.35) was treated with benzoyl chloride in the presence of pyridine, the bisbenzoate was formed, and after purification, it was subjected to hydrolysis using aqueous barium hydroxide [Ba(OH)2]. The benzoyl group attached to the primary amine underwent hydrolysis to produce a-benzoylamino-5-aminopentanoate, which, after acidification, was treated with cyanamide (N=C-NH2) to form a-benzoylamino-5-guanidopentanoic acid. A final hydrolysis of the benzoyl group with dilute aqueous hydrochloric acid (HCl) generated arginine (Arg, R) (Scheme 12.36). 

The cis and tram isomers of an unsaturated azlactone were obtained for the first time by this method. a-Benzoylamino-/3-methoxybuwith acetic anhydride yields a mixture of the isomeric benzoylaminocrotonic azlactones. The labile isomer is less soluble and hence readily isolated in the pure state. It is rapidly converted into the stable isomer by heat or by the action of cold pyridine. The two isomeric benzoylaminocinnamic azlactones have been prepared in a similar manner. ... 

Metal-mediated Reaction. The o -position of this inner salt can undergo dehydrogenative cross-coupling with terminal aUcynes, such as phenylacetylene, under Cu-mediated reaction conditions. The a-alkynyl derivative readily cyclizes in situ with the loss of the Ts group to afford 2-phenylpyrazolo[ l,5-a]pyridine in a 22% yield. This inner salt does not work as well as the analogous l-(benzoylamino)pyridinium inner salt in this reaction. ... 

Benzoylamino-2-methyl-l-propanol allowed to react at —30 to —40° with p-toluenesulfonyl chloride in pyridine, and the product isolated after ca. 15 min. -> 4,4-dimethyl-2-phenyl-2-oxazoline. Y 84%.—The amido group may be attached to prim., sec., or tert. carbon and the alcohol may be prim, or sec. Yields vary widely depending on the structure of the startg. m. F. e. s. R. N. Boyd and R. C. Rittner, Am. Soc. 82, 2032 (1960). 

---