摘要:
The tetracycline class of antibiotics has played a major role in the treatment of infectious diseases for the past 50 years. However, the increased use of the tetracyclines in human and veterinary medicine has led to resistance among many organisms previously thought susceptible to tetracycline antibiotics. The recent development of a modular synthesis of tetracycline analogs through a chiral enone intermediate has allowed for the efficient synthesis of novel tetracycline analogs never prepared before. The present invention provides more efficient routes for preparing the enone intermediate and allows for substituents at positions 4a, 5, 5a, and 12a of the tetracycline ring system.
摘要:
A process for preparation of protriptyline hydrochloride from 5- dihydrobenzocycloheptatriene of formula (1) by coupling with chloropropyl alcohol in the presence of excess n-butyl Lithium in tetrahydrofuran under inert atmosphere, followed by preparation of mesylate derivative of formula (3) and finally the nucleophilic displacement of the mesylate group by reacting methylamine solution in methanol to give protriptyline free base of the formula (4). Also the present process reveals the hydrochloride salt formation and purification of the same to give pure pharmaceutical grade protriptyline hydrochloride with impurities less than 0.1%w/w.
摘要:
One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.
摘要:
One aspect of the present invention relates to novel ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject processes provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.
摘要:
One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.
摘要:
This invention describes a process for covalently coupling organic compounds which comprises reacting an olefinic compound having a halogen or halogen-like substituent at a coupling position with a diboron derivative in the presence of a Group VIII metal catalyst and a suitable base. The invention also describes a process for preparing alkene borate intermediates comprising reacting an olefinic compound having a halogen or halogen-like substituent with a diboron derivative in the presence of a Group VIII metal catalyst and a suitable base.
摘要:
The process forms an alkyl aralkyl ketone from an aralkenyl secondary alcohol having an allylic double bond relative to the hydroxycarbinyl group, and having the allylic double bond positioned between the aryl moiety and the hydroxycarbinyl group. This is accomplished by heating the alcohol in a chemically indifferent organic liquid medium to which a catalytic quantity of an iron polycarbonyl has been added, so that an internal rearrangement occurs. Among the ketones that can be efficiently produced in this manner is non-steroidal antiinflammatory agent, 4-(6'-methoxy-2'-naphthyl)-butan-2-one, generally known as nabumetone.
摘要:
Ein Verfahren zur Herstellung mehrkerniger aromatischer Verbindungen durch Kreuzkupplung von terminalen Alkinen mit aromatischen Halogenverbindungen oder - Perfluoralkylsulfonaten unter Palladiumkatalyse in Gegenwart mindestens eines wasserlöslichen Komplexliganden, dadurch gekennzeichnet, daß das Reaktionsmedium eine wäßrige und eine organische Phase bildet und das Palladium in Form einer in der organischen Phase löslichen Palladiumverbindung oder in fester Form als Palladiummetall, insbesondere auf einem Träger aufgebracht, zugesetzt wird. Die erfindungsgemäße Reaktion verläuft chemoselektiv, so daß selbst elektrophile Gruppen, wie Ester oder Nitrile, den Verlauf der Reaktion nicht beeinträchtigen. Durch das erfindungsgemäße Verfahren lassen sich organische Verbindungen ökonomisch in sehr guten Ausbeuten und gleichzeitig sehr hoher Reinheit, insbesondere ohne Verunreinigung durch die Komplexliganden, herstellen.