- A methylprednisolone production process and production apparatus (by machine translation)
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The invention discloses a methylprednisolone production device, including connected according to the procedure of the reaction, shui xifu, centrifugal filtration equipment, the concentrator, [...], biological fermentation tank, drying apparatus, the drying apparatus comprises an outer cylinder, the drying cylinder, the inner cylinder; the bottom surface of the outer cylinder is provided with a motor, the rotation of the motor shaft is provided with a exhaust fan blade, type impeller, vortex impeller; exhaust fan leaf is arranged on the bottom surface of the drying cylinder between the cylinder and the outer cylinder; drum type impeller is arranged on the drying cylinder between the cylinder and an inner cylinder; vortex impeller is arranged on the bottom of the inner drum; [...] is set with infrared heating in; on the inner end center provided with a feed port; the outer tube side wall comprises an inner wall and the outer wall; the inner wall and the outer wall of the annular cavity formed between the interlayer; outlet at upper end of the sandwich cavity is provided with an annular baffle plate; the baffle plate is provided with a vent; the upper end of the baffle is provided with a rotatable air purifies the link. This invention can reduce the methylprednisolone intermediate product in the production process of the preparation time, realize methylprednisolone rapid high-quality production. (by machine translation)
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- 9α-dehalogenation process
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The present invention involves improved processes for the dehalogenation of 9α-halosteroids (I) STR1 to produce the corresponding 11β-hydroxy steroids (II) STR2 which are known to be useful as pharmaceutical, where the improvements comprise (1) adding the 9α-halo steroid (I) to the chromium and (2) using catalytic amounts of chromium in the presence of a means of converting chromium (II) to chromium (III).
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- Process and intermediates for the preparation of 17 alphahydroxyprogesterones and corticoids from an enol steroid
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This invention discloses an improved process for the production of corticoids from 17α-hydroxy steroids utilizing peroxymonosulfate.
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- Carboxyl group catalysis of acyl transfer reactions in corticosteroid 17- and 21-monoesters
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Succinate esters, although frequently employed as water-soluble prodrugs of poorly soluble parent drugs, are not sufficiently stable to allow long-term storage in solution. Intramolecular catalysis of ester hydrolysis by the terminal succinate carboxyl group is a contributing factor to this instability. Methylprednisolone 21-succinate has recently been reported to undergo both hydrolysis and 21 ? 17 acyl migration in aqueous solutions. Intramolecular catalysis by the terminal carboxyl group is seen in both reactions, but the catalytic mechanisms are not well understood. While acyl migration can only be catalyzed via the carboxyl group acting as a general acid or general base, hydrolysis may undergo either nucleophilic or general acid-base catalysis. To gain further insight into the catalytic mechanism, hydrolysis of methyl-prednisolone 21-succinate was carried out in aniline buffers to trap any succinic anhydride (as the anilide) that would form if the catalysis were nucleophilic. The nucleophilic mechanism was shown to account for only 15-20% of the overall catalysis. Comparisons of the rates of the intramolecularly catalyzed reactions of methylprednisolone 21- and 17-succinate were made with the same reactions of methylprednisolone-21- and 17-acetate catalyzed intermolecularly by acetate ion. Interestingly, intramolecular catalysis appears to favor acyl migration over hydrolysis. Hence, the hydrolysis of methylprednisolone 21-succinate is faster in basic solutions (pH > 7.4), while acyl migration becomes the dominant reaction in the catalyzed region of the pH profile between pH 3.6 and 7.4. Arguments are presented to account for these differences in catalytic efficiency in terms of the transition-state structures for the two reactions.
- Anderson,Conradi,Lambert
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p. 604 - 610
(2007/10/02)
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