- Copper(II)-Catalyzed Reactions of α-Keto Thioesters with Azides via C-C and C-S Bond Cleavages: Synthesis of N-Acylureas and Amides
-
Cu(II)-catalyzed reaction of α-keto thioesters with trimethylsilyl azide (TMSN3) proceeds with the transformation of the thioester group into urea through C-C and C-S bond cleavages, constituting a practical and straightforward synthesis of N-acylureas. When diphenyl phosphoryl azide (DPPA) is used instead as the azide source in an aqueous environment, primary amides are formed via substitution of the thioester group. The reactions are proposed to proceed through Curtius rearrangement of the initially formed α-keto acyl azide to generate an acyl isocyanate intermediate, which reacts further with an additional amount of azide or water and rearranges to afford the corresponding products. To demonstrate the potentiality of the method, one-step syntheses of pivaloylurea and isovaleroylurea, displaying anticonvulsant activities, have been carried out.
- Maity, Rajib,Naskar, Sandip,Das, Indrajit
-
p. 2114 - 2124
(2018/02/23)
-
- Solid-phase synthesis of disubstituted N -acylureas from resin-bound ureas and acyl chlorides
-
Acylureas (ureides) are valued for their important biological activities. Whereas cyclic acylureas have frequently been the object of solid-phase chemistry, only few reports have focused on the solid-supported preparation of acyclic representatives. We have prepared different types of acylureas on Rink amide resin in three or four steps. The products are either N-acylated (9, 18), N-acylated-N′-alkylated (10, 19), or N-acylated-N-alkylated (22). Characteristic NMR parameters of isomeric acylureas 10, 19, and 22 are discussed.
- Haecker, Hans-Georg,Meusel, Manuela,Aschfalk, Melanie,Guetschow, Michael
-
experimental part
p. 59 - 64
(2011/04/15)
-
- DIHYDROURACIL COMPOUNDS AS ANTI-ICTOGENIC OR ANTI-EPILEPTOGENIC AGENTS
-
Methods and compounds useful for the inhibition of convulsive disorders, including epilepsy, are disclosed. The methods and compounds of the invention inhibit or prevent or treat ictogenesis, epileptogenesis, or epileptogenesis-associated conditions. Methods for preparing the compounds of the invention are also described. Particularly preferred compounds of the invention include Formula 1 as described herein.
- -
-
-
- Thermal reaction of cinnamic acid and of β-styrylphosphonic acid with urea
-
The thermal reaction of b-styrylphosphonic acid under experimental conditions similar to those applied to cinnamic acid and to methyl cinnamate to provide 6-phenyl-5,6-dihydrouracil, led to the formation of the novel 6-phenyl-5,6-dihydro-4-phosphorylamide-(1H,3H)-2-pyrimidinone.
- Vuano,Pieroni,Cabaleiro
-
p. 318 - 320
(2007/10/03)
-