摘要:
Crystalline polymorphous forms of rifaximin (INN) antibiotic named rifaximin α and rifaximin β, and a poorly crystalline form named rifaximin γ, useful in the production of medicinal preparations containing rifaximin for oral and topical use and obtained by means of a crystallization carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a determinate temperature and for a determinate period of time, followed by a drying carried out under controlled conditions until reaching a settled water content in the end product, are the object of the invention.
摘要:
Crystalline polymorphous forms of rifaximin (INN), referred to as rifaximin α and rifaximin β, and a poorly crystalline form referred to as rifaximin γ, useful in the production of medicaments containing rifaximin for oral and topical use and obtained by means of a crystallization process carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a fixed temperature and for a fixed period of time, followed by a drying under controlled conditions until reaching a precise water content in the end product, are the object of the invention.
摘要:
At the present invention relates to a new process for the preparation of the (S)-naproxen 4-nitrooxybutyl ester and to new intermediates obtained and used therein. The invention further relates to the use of the new intermediates for the manufacturing of pharmaceutically active compounds such as (S)-naproxen 4-nitrooxybutyl ester. The invention also relates to the use of (S)-naproxen 4-nitrooxybutyl ester prepared according to the process of the present invention for the manufacturing of a medicament for the treatment of pain.
摘要:
A process for manufacturing 1-(3-trifluoromethyl)phenyl-propan-2-one intermediate in the synthesis of the anorexic drug fenfluramine consists of reacting the diazonium salt of 3-trifluoromethylaniline with isopropenyl acetate in a polar solvent in the presence of a catalytic amount of a cuprous salt and, optionally, of a base and purifying the crude product through the bisulfite complex or distillation under vacuum.
摘要:
A new process for the optical resolution of racemic mixtures of .alpha.-naphthylpropionic acids of formula ##STR1## wherein R.sub.1 is (C.sub.1-6) alkyl and R.sub.2 represents hydrogen or a halogen atom comprises reacting a racemic mixture of a compound of formula II ##STR2## wherein R.sub.1 and R.sub.2 have the above seen meanings and R.sub.3 is a reactive group, with an optically active aminoacid of formula ##STR3## wherein R.sub.4 represents a (C.sub.1-8) alkyl, phenyl, substituted phenyl, benzyl, substituted benzyl or carboxy, and m is an integer from 0 to 4, to give a pair of diastereoisomeric amides of formula ##STR4## wherein R.sub.1, R.sub.2, R.sub.4 and m have the above seen meanings, and M is a hydrogen atom or a cation of an alkali metal or a cation of an organic base. Compounds IV are resolved into the single diastereoisomeric amides d,d or 1,d, or d,1 or 1,1. Acid hydrolysis gives the optically active compound I.
摘要:
A new process for the synthesis of pyrido-imidazo-rifamycins of formula ##STR1## wherein R is hydrogen or acetyl, R.sub.1 and R.sub.2 independently represent hydrogen, (C.sub.1-4)-alkyl, benzyloxy, mono- or di-(C.sub.1-3)-alkylamino-(C.sub.1-4)-alkyl, (C.sub.1-3)-alkoxy-(C.sub.1-4)-alkyl, hydroxymethyl, hydroxy-(C.sub.2-4)-alkyl, cyano, halogen, nitro, mercapto, (C.sub.1-4)-alkylthio, phenylthio, carbamoyl, mono- or di-(C.sub.1-4)-alkyl-carbamoyl, or R.sub.1 and R.sub.2 taken together with two consecutive carbon atoms of the pyridine nucleus form a benzene ring optionally substituted by one or two methyl or ethyl groups.The process comprises reacting the rifamycin O of formula ##STR2## with a 2-aminopyridine of formula ##STR3## wherein R.sub.1 and R.sub.2 have the same meanings as before.
摘要:
A new process for the optical resolution of mixtures of d- and 1-2-(6-methoxy-2-naphthyl)-propionic acids, which comprises preparing a solution of a mixture of d-and 1-2-(6-methoxy-2-naphthyl)-propionic acids and an optically active organic base in a predetermined organic solvent, slowly cooling the obtained solution and seeding with crystals of a salt of d-2-(6-methoxy-2-naphthyl)-propionic acid with the optically active organic base containing a certain amount by weight of the organic solvent, and treating the obtained product with mineral acids in suitable organic solvents to obtain the free d-2-(6-methoxy-2-naphthyl)-propionic acid.