Efficient Synthesis of a Highly Selective NPY-5 Receptor Antagonist: A Drug Candidate for the Treatment of Obesity
摘要:
A concise and practical synthesis of highly selective NPY-5 receptor antagonist 1 is described. The animopyrazine intermediate 3 was synthesized via either monobromination of aminopyrazine or palladium-catalyzed regioselective debromination of dibromopyrazine followed by an efficient Suzuki-Miyaura coupling. For the preparation of the spirolactone piperidine 2, significantly improved yield was achieved by using a combination of n-BuMgCl and n-BuLi. This protocol also dramatically increased the thermal stability of the aryllithium intermediate and eliminated the requirement for costly cryogenic conditions. The union of the spirolactone piperidine 2 and aminopyrazine 3 via a carbonyl group was accomplished using phenyl chloroformate delivering the target molecule in high yield.
Process for making spiro isobenzofuranone compounds
申请人:——
公开号:US20020151456A1
公开(公告)日:2002-10-17
This invention relates to a process for making spiro isobenzofuranone compounds by coupling of an aminopyrazine fragment with a spirolactone piece.
这项发明涉及一种通过将氨基吡唑片段与螺内酯片段偶联制备螺环异苯并呋喃酮化合物的方法。
Method of substituent introduction through halogen-metal exchange reaction
申请人:Kato Shinji
公开号:US20050104233A1
公开(公告)日:2005-05-19
A method of exchanging a halogen atom of a halide, which has a group containing an acidic proton and in which one or more halogen atom(s) is/are substituted on a carbon atom of the carbon-carbon double bond, with a metal atom by halogen-metal-exchange reaction and introducing an electrophilic reagent into the carbon atom to which the metal atom is attached. The above method is an industrially excellent method of introducing a substituent by halogen-metal exchange reaction.