On June 30, 2011, Badiger, Sangamesh; Behnke, Dirk; Betschart, Claudia; Chaudhari, Vinod; Cotesta, Simona; Hinrichs, Juergen Hans-Hermann; Ofner, Silvio; Pandit, Chetan published a patent.Quality Control of tert-Butyl 1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate The title of the patent was Preparation of diaza-spiro[5.5]undecanes as orexin receptor antagonists. And the patent contained the following:
The title compounds I [A = (un)substituted 8-10 membered fused bicyclic aromatic ring system which may contain from 1-4 heteroatoms selected from N, O and S, wherein the ring system may contain not more than 2 O atoms and not more than 2 S atoms; or A = (un)substituted 5-6 membered monocyclic aromatic ring system which may contain 1-4 heteroatoms selected from N, O and S, wherein the ring system may contain not more than 2 O atoms and not more than 2 S atoms; m = 0-6; n = 0-6; R1, R2 = halo, alkyl, haloalkyl, etc.; X1 = C(O) and X2 = N(LB); or X1 = N(LB) and X2 = C(O); L = C(R7)2; R7 = H, alkyl, haloalkyl, etc.; B = (un)substituted 5-10 membered monocyclic or fused polycyclic aromatic ring system which may contain from 1-4 heteroatoms selected from N, O and S, wherein the ring system may contain not more than 2 O atoms and not more than 2 S atoms], were prepared E.g., a multi-step synthesis of II, starting from indole-3-carboxaldehyde, was described. Exemplified compounds I were tested for inhibition of orexin-1 and orexin-2 receptors binding (data provided). Pharmaceutical compositions comprising the compound I, alone or in combination with other therapeutic agent, were also disclosed. The experimental process involved the reaction of tert-Butyl 1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate(cas: 1198284-94-4).Quality Control of tert-Butyl 1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate
The Article related to diazaspiroundecane preparation orexin receptor antagonist, Heterocyclic Compounds (More Than One Hetero Atom): Pyrazines and Quinoxalines (Including Piperazines) and other aspects.Quality Control of tert-Butyl 1-oxo-2,9-diazaspiro[5.5]undecane-9-carboxylate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics