- Ketoserin intermediate and preparation method of ketoserin
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The invention discloses a preparation method of a ketoserin intermediate 2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone and a preparation method of ketoserin, and the reaction equation of the preparation method of the ketoserin intermediate 2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone is shown in the specification: in the reaction, sodium carbonate and acetonitrile are used, no catalyst is added, inorganic salt is removed through hot filtration after the reaction, filtrate is evaporated to dryness, acetonitrile is recycled, and an intermediate 04, namely the ketoserin intermediate2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone, is obtained. The method is simple and convenient to operate, lower in cost, better in product character and more beneficial to synthesis of a finalproduct.
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- Reinvestigation of the synthesis of ketanserin (5) and its hydrochloride salt (5.HCl) via 3-(2-chloroethyl)-2,4-(1H,3H)-quinazolinedione (2) or dihydro-5H-oxazole(2,3-b)quinazolin-5-one (1)
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The synthesis of ketanserin (5) and its hydrochloride salt (5.HCl) using respectively equimolar amounts of 3-(2-chloroethyl)-2,4-(1H,3H)-quinazolinedione (2) with 4-(parafluorobenzoyl)piperidine (3) and dihydro-5H-oxazole(2,3-b) quinazolin-5-one (1) with hydrochloride salt of 4-(parafluorobenzoyl)piperidine (3.HCl) is reinvestigated. The one-pot reaction of ethyl-2-aminobenzoate with ethyl chloroformate and ethanol amine has afforded 3-(2-chloroethyl)-2,4-(1H,3H) -quinazolinedione (2) (86%) that was then refluxed with 4-(parafluorobenzoyl) piperidine (3) in ethyl methyl ketone in the presence of sodium carbonate to obtain free base of ketanserin (87%). In another attempt, a very pure hydrochloride salt of ketanserin (5.HCl) was synthesized using equimolar amounts of dihydro-5H-oxazole(2,3-b)quinazolin-5-one (1) and hydrochloride salt of 4-(parafluorobenzoyl)piperidine (3.HCl) by a solvent-less fusion method. Thus, under optimized conditions, 180°C and a reaction time of 30 min, the powder mixture was transformed into glassy crystals that were initially readily soluble in chloroform but were transformed afterwards over time (2 h) to white precipitates (5.HCl) suspended in chloroform with a yield of 72%.
- Fakhraian, Hossein,Heydary, Mehdi
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p. 151 - 156
(2014/02/14)
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- Floating pharmaceutical composition comprising an active phase and a non-active phase
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The invention concerns a floating pharmaceutical composition consisting of at least a first phase comprising at least a high dose active principle combined with one or several carriers and at least a second phase comprising at least a gas-generating system. The invention also concerns tablets comprising such a pharmaceutical composition and a method for preparing such tablets.
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- Piperidinylalkyl quinazoline compounds, composition and method of use
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Novel quinazoline derivatives, comprising in the heterocyclic part of their quinazoline nucleus at least one carbonyl or thiocarbonyl group and a particularly substituted piperidinyl-alkyl side chain, said compounds being potent serotonin-antagonists.
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