摘要:
A process for preparing fexofenadine is described, which provides for the hydrolysis of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidyl]-1-oxobutyl]-α,α-dimethylbenzeneacetic acid-alkyl ester, in a mixture of water and optionally an organic solvent, in the presence of a base; the carboxylate salt of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidyl]-1-oxobutyl]-α,α-dimethylbenzeneacetic acid is thus obtained, which is then directly reduced as carboxylate in a basic environment with hydrogen in the presence of a suitable hydrogenation catalyst to give the carboxylate of fexofenadine, which is precipitated by neutralization of the solution.
摘要:
A process for preparing fexofenadine is described, which provides for the hydrolysis of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidyl]-1-oxobutyl]-α,α-dimethylbenzeneacetic acid-alkyl ester, in a mixture of water and optionally an organic solvent, in the presence of a base; the carboxylate salt of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidyl]-1-oxobutyl]-α,α-dimethylbenzeneacetic acid is thus obtained, which is then directly reduced as carboxylate in a basic environment with hydrogen in the presence of a suitable hydrogenation catalyst to give the carboxylate of fexofenadine, which is precipitated by neutralisation of the solution.
摘要:
The present invention refers to a new process for the synthesis of tapentadol comprising the quantitative resolution of the racemic mixture (V) to obtain the stereoisomer of (S)-3-(dimethylamino)-2-methyl-1-(3-nitrophenyl)-propan-1-one (VII) according to the Scheme 2 below using the (2R,3R)—O,O′-dibenzoyltartaric chiral acid wherein said resolution is quantitative. The present invention also refers to some intermediate compounds of the new synthesis process of tapentadol.
摘要:
The object of the present invention is a new process for the synthesis of tapentadol, both as free base and in hydrochloride form, which comprises the step of alkylation of the ketone (VII) to yield the compound (VIII), as reported in Diagram 1, with high stereoselectivity due to the presence of the benzyl group as substituent of the amino group. It was surprisingly found that this substitution shifts the keto-enol equilibrium towards the desired enantiomer and amplifies the capacity of the stereocenter present in the compound (VII) to orient the nucleophilic addition of the organometallic compound at the carbonyl towards the desired stereoisomer. This substitution thus allows obtaining a considerable increase of the yields in this step, and consequently allows significantly increasing the overall yield of the entire tapentadol synthesis process.A further object of the present invention is constituted by the tapentadol free base in solid form, obtainable by means of the process of the invention.Still another object of the invention is represented by the crystalline forms I and II of the tapentadol free base.A further object of the present invention is the mixture of the crystalline forms I and II of the tapentadol free base.
摘要:
The object of the present invention is a new process for the synthesis of tapentadol, both as free base and in hydrochloride form, which comprises the step of alkylation of the ketone (VII) to yield the compound (VIII), as reported in Diagram 1, with high stereoselectivity due to the presence of the benzyl group as substituent of the amino group. It was surprisingly found that this substitution shifts the keto-enol equilibrium towards the desired enantiomer and amplifies the capacity of the stereocenter present in the compound (VII) to orient the nucleophilic addition of the organometallic compound at the carbonyl towards the desired stereoisomer. This substitution thus allows obtaining a considerable increase of the yields in this step, and consequently allows significantly increasing the overall yield of the entire tapentadol synthesis process.A further object of the present invention is constituted by the tapentadol free base in solid form, obtainable by means of the process of the invention.Still another object of the invention is represented by the crystalline forms I and II of the tapentadol free base.A further object of the present invention is the mixture of the crystalline forms I and II of the tapentadol free base.
摘要:
The present invention refers to a new process for the synthesis of tapentadol comprising the quantitative resolution of the racemic mixture (V) to obtain the stereoisomer of (S)-3-(dimethylamino)-2-methyl-1-(3-nitrophenyl)-propan-1-one (VII) according to the Scheme 2 below using the (2R,3R)—O,O′-dibenzoyltartaric chiral acid wherein said resolution is quantitative.The present invention also refers to some intermediate compounds of the new synthesis process of tapentadol.
摘要:
A process for preparing fexofenadine is described that includes the purification of 4-[4-chloro-1-oxobutyl]-2,2-dimethylphenyl acetic acid alkyl ester by means of suspension in a hydrocarbon, preferably n-heptane. The compound thus obtained is dissolved in a suitable solvent and condensed with azacyclanol to give the compound shown below where R is an alkyl radical, which is then hydrolysed and reduced to give fexofenadine.
摘要:
System for connecting section boards, particularly panel-like elements having rectangular greater surfaces and horizontal greater sides to form partition walls includes two metal sections intended to connect a lower sectional board to an upper sectional board, one metal section being attached to the upper greater horizontal side of the lower sectional board and the other metal section being attached to the lower greater horizontal side of the upper sectional board, said metal sections being connected to each other by means of a tongue-and-groove joint and forming, once they are connected together, a recessed portion extending along the greater horizontal side of the sectional boards and intended to receive and hold therein a corresponding portion of an element or fixture intended to project or to hang from the partition wall.
摘要:
A process is disclosed for pressing a material selected from materials of vegetable and animal origin. The process includes the steps of mechanically compressing the material of vegetable or animal origin while simultaneously vibrating the material at an ultrasonic frequency. The ultrasonic frequency going through the material modifies the material's internal state so as to considerably reduce resistance offered by the material to mechanical compression.
摘要:
A device for slowing a downward movement of a sliding door of a wardrobe includes a free-wheel consisting of a driving portion and a driven portion. The driven portion is coaxially aligned with the driving portion and is provided with an external toothing. The device also includes a driving rope running through the free-wheel driving portion which is fastened at one end to the sliding door and at another end, by interposition of a tension spring, to a base of the wardrobe. Additionally a spring is arranged between the free-wheel driving and driven portions and is used to engage the two free-wheel portions during the downward movement of the sliding door and to disengage the two during upward movement of the sliding door. A centrifugal brake is coupled to a spindle which is provided with an external toothing cooperating with the external toothing of the free-wheel driven portion. The centrifugal brake is used to generate a resisting torque capable of braking the free-wheel driving and driven portions and slowing the downward movement of the sliding door.