Spirodecanone refers to a class of spirocyclic ketones, often studied for their potential applications in medicinal chemistry. One notable example is 1-Phenyl-1,3,8-triazaspiro[4.5]decan-4-one, which has been investigated as a metabolite of neuroleptic agents like Fluspirilene. It has a molecular formula of and a melting point of 188-191 ðC.
The original synthesis was first disclosed by Paul Janssen, and was covered by Daniel Lednicer in one of his books.
A recent synthesis of spirodecanone is disclosed:
The Strecker-like condensation between N-benzyl-4-piperidone [3612-20-2] (1), aniline and TMSCN [7677-24-9], gives 4-anilino-1-benzylpiperidine-4-carbonitrile [968-86-5] (2). Acid catalyzed partial hydrolysis of the nitrile to the amide afforded 4-anilino-1-benzylpiperidine-4-carboxamide [1096-03-3] (3). Reaction with forms the spiroimidazolidone ring giving 8-benzyl-1-phenyl-1,3,8-triazaspiro[4.5]dec-2-en-4-one [974-42-5] (4). The imine bond is reduced with sodium borohydride giving 8-benzyl-1-phenyl-1,3,8-triaza-spiro[4.5]decan-4-one [974-41-4] (5). Catalytic hydrogenation then removes the benzyl group (6).
It is noteworthy to mention that intermediate 4 finds dual use in the synthesis of some highly potent fentanyl analogs.
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