Recyclization of 2-methoxy-5-morpholino-1,3-oxazole-4-carbonitrile by benzylamine, phenethylamine, and phenylhydrazine

Methods for the synthesis of 1-substituted 1H-imidazol-2(3H)-ones

“…[100][101][102] The interaction of 4,5-diphenyloxazol-2(3H)-one (66a) with primary amines 13 gave the respective 1-substituted 4,5-diphenyl-1H-imidazol-2(3H)-ones 1, with subsequent formation of intermediates AK and AL (Scheme 75). 100 When benzyl-and cyclohexylamines 13f,g were used in the reaction, small amounts of N,N'-disubstituted ureas 4c,d were also isolated from the reaction mixture, apparently formed by transamination of the intermediate β-oxourea AK.…”

“…100,101 The possible ANRORC-type mechanism for the formation of compounds 1 includes nucleophilic substitution of methoxy group by residue of arylamine AM, attack by water molecule resulting in opening of oxazole ring (intermediate AN), and subsequent cyclization with the formation of imidazolone derivative AO, then converting to the tautomeric imidazolone 1.…”

Recyclization of 5‐Amino‐ oxazoles as a Route to new Functionalized Heterocycles (Developments of V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the NAS of Ukraine)

“…they can be hydrolysed in an acidic medium, forming imidazolidine-2,4-dione derivatives 23; and for the last ones only the keto form was established. [16] Notably, in addition to compounds 22, the products of deep degradation of the substrate (oxalate acid diamides) were present in a small amount in the reaction mixture.…”

“…Nucleophilic substitution of its methoxy group by the primary amines and subsequent hydrolysis led to recyclization through the possible non‐cyclic intermediate 21 . The products of recyclization (compounds 22 ) exist in the enamine tautomeric form, but they can be hydrolysed in an acidic medium, forming imidazolidine‐2,4‐dione derivatives 23 ; and for the last ones only the keto form was established [16] . Notably, in addition to compounds 22 , the products of deep degradation of the substrate (oxalate acid diamides) were present in a small amount in the reaction mixture.…”

Synthesis of novel phosphorylated peptidomimetics which contain ω-haloalkyl and ω-thiocyanoethyl residues

“…It is known that 1,3-oxazole derivatives are reactive compounds and can be converted to other fiveand six-membered rings. [1][2][3][4][5][6][7][8][9][10] In addition, 1,3-oxazoles are unstable in an acidic medium and are cleaved by a water molecule to form acyclic products. 11,12 In the case of 4-functionalized 5-amino-1,3-oxazoles, this leads to formation of compounds of peptide nature.…”