Synthesis of 4′-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-ones
摘要:
N-Boc-protected 8-azaspiro[bicyclo[3.2.1]octane-3,2'-oxirane] reacted with primary aliphatic amines through opening of the epoxide ring with formation of the corresponding amino alcohols which were converted into N-chloroacetyl derivatives. The latter underwent cyclization to N-Boc-protected 4'-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2'-morpholin]-5'-ones by the action of sodium hydride in DMF, and subsequent treatment with hydrogen chloride in ethyl acetate afforded 8-azaspiro[bicyclo[3.2.1]octane-3,2'-morpholin]-5'-one hydrochlorides.