- Facile entry to ethyl tetrahydro-1H-pyrrolizin-7a(5H)-ylacetate: A versatile pharmaceutical intermediate
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An improved synthesis of ethyl tetrahydro-1H-pyrrolizin-7a(5H)-ylacetate is reported. This valuable pharmaceutical intermediate was easily obtained from 1,7-diiodo-4-heptanone in 46% yield, thus improving the procedure reported in the literature (23% yield) which starts from 1,7-dichloro-4-heptanone. Moreover, 1,7-diiodo-4-heptanone was obtained as an easily manageable solid, in this being preferable to its 1,7-dichloro isologue, which is a quite unstable oil. The former was synthesized in high overall yield (75%) starting from the commercially available diethyl 4-oxoheptanedioate, thus overtaking the well-known problems related to the use of γ-butyrolactone. The Japan Institute of Heterocyclic Chemistry.
- Bruno, Claudio,Catalano, Alessia,Lentini, Giovanni,Carocci, Alessia,Franchini, Carlo,Tortorella, Vincenzo
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- Preparation method of intermediate of synthesis of pilsicainide hydrochloride
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The invention provides a preparation method of an intermediate for synthesis of pilsicainide hydrochloride. The method comprises the following steps: step 1, performing a polymerization reaction on butyrolactam (I) and gamma-butyrolactone (II) under strong base and predetermined conditions to form N-(3-carboxypropyl)butyrolactam (III); step 2, performing cyclization on the N-(3-carboxypropyl)butyrolactam(III) at a high temperature in a monoisopropyl malonate solvent, performing condensation on the cyclization product and a monoester malonate to form 7alpha-pyrrolizine-acetate, wherein preferred choice is to produce 7alpha-pyrrolizine-isopropyl acetate (V); and step 3, performing hydrolysis on the 7alpha-pyrrolizine-acetate in an acid to form the corresponding pharmaceutically-acceptable salt. The preparation method provided by the invention avoids expensive or difficult-to-obtain raw materials, avoids use of liquid ammonia in the synthetic process, reduces the reaction steps, and has simple operation, less three waste (waste water, waste gas and solid waste) and a high yield.
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Paragraph 0068-0077
(2019/07/11)
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- Synthesis and muscarinic activity of a series of quinolines and naphthalenes with a 1-azabicyclo[3.3.0]octane moiety
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In order to discover a medicine effective against Alzheimer's disease, we synthesized a series of quinoline derivatives having a characteristic 1- azabicyclo[3.3.0]octane amine ring, and performed pharmacological evaluation of them. Acetylcholine esterase inhibitory activities of these derivatives were unexpectedly weak. Tests for central nervous muscarinic cholinergic receptor binding affinity indicated that these compounds had higher affinities to muscarinic M1 receptors than to M2 receptors. A series of naphthalene derivatives substituted with the 1-azabicyclo[3.3.0]octane ring were also synthesized and muscarinic M1 and M2 receptor binding affinity determined. These compounds had much higher affinity for M1 receptors than the quinoline derivatives, and 1-[N-(1-azabicyclo[3.3.0]octan-5-yl)methyl-N- methylamino]-4-nitronaphthalene showed the highest affinity and selectivity. The ability of this compound to improve cognitive function was assessed using the passive avoidance test in scopolamine-induced mice.
- Suzuki, Tomoo,Usui, Toshinao,Oka, Mitsuru,Suzuki, Tsunemasa,Kataoka, Tadashi
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p. 1265 - 1273
(2007/10/03)
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- A NEW ROUTE TO 8-SUBSTITUTED PYRRAZOLIZIDINES
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A new route to 8-substituted pyrrazolizidines starting with Δ4(8)-dehydropyrrolizidinium perchlorate is described.
- Miyano, Seiji,Yamashita, Osamu,Fujii, Shinichiro,Somehara, Takao,Sumoto, Kunihiro
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p. 755 - 758
(2007/10/02)
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