Studies on heterocyclic compounds. XXXIV. Synthesis of 2-substituted aminobenzoxazoles with nickel peroxide.

Syntheses, structures and bioactivities of fluorine-containing phenylimino-thia(oxa)zolidine derivatives as agricultural bioregulators

“…2-Aryl aminobenzoxazoles were generally synthesized by cyclodesulfurization of N-(2-hydroxyphenyl)-N 0 -phenylthioureas with nickel peroxide [32], potassium superoxide [33] and dicyclohexylcarbodiimide [34], or by treatment of 2-chlorobenzoxazole with aniline in THF [35]. It was also very difficult for us to synthesize fluorophenyl aminobenzoxazoles with using the known synthetic method for non-fluoro-counterpart, as the presence of too strong electron-withdrawing fluoro-group.…”

Chiral 1,1′‐Binaphthyl Molecular Clefts for the Complexation of Excitatory Amino‐Acid Derivatives

“…Light-pink oil. IR (CHCl,) ( i)-6.6'-Dibr~mo-2,2'-bis(dode~yloxy/-7,7'-dim~thoxy-l,l~-binuphth.~l (30). To a soh.…”

“…Compounds 36-41 bear two N-(pyridine-6,2-diyl)urea moieties, whereas compound 42 incorporates two N-( 1,8-naphthyridine-7,2-diyl)acetamide residues for H-bonding at the major groove. For the Suzuki coupling leading to the receptors 3 U 1 , the brominated N-(pyridin-2-yl)ureas 34 and 35 were prepared by addition of 6-bromopyridin-2-amine to butyl isocyanate and phenyl isocyanate, respectively [30]…”

Studies on the reactivity of some N‐aryl‐ and N‐heteroaryl‐N'‐alkylthioureas towards electrophilic reagents. Synthesis of new N‐pyridylthioureas and thiazolines maría

“…The formation of (4-pyridyl)thioureas was regioselective since only one isomer was obtained 2(a,b), that in both series was identified as the result of the substitution on the NH(1) of the thiourea moiety. Concerning the formation of ureas 3(a,b), it can be presumed that the reaction proceeded through the initial formation of a S- (4-pyridyl) intermediate, that was immediately hydrolyzed to afford the corresponding urea, in accordance to a precedent work [16]. The role of 4-chloropyridine in these transformations was probed, since when thioureas 1(a,b) were refluxed with 2-propanol containing hydrogen chloride for 24 hours only starting materials were recovered.…”