摘要:
Disclosed is a process which can be used on an industrial scale for preparing and purifying 1,7′-dimethyl-2′-propyl-2,5′-bi-1H-benzimidazole in which the crude product is subjected to charcoal treatment.
摘要:
The invention relates to a method for producing 1,3-dioxolane-2-ones of general formula (3) in basic reaction conditions by reesterifying the respective ester of general formula (1) in which R1 to R5 have the meanings indicated in the claims and the description. The invention further relates to a method for producing 2-hydroxy carboxylic acid esters of general formula (5) with or without isolation of the intermediate in the form of a derivative of the 1,3-dioxolane-2-one of general formula (3) in basic reaction conditions by reesterifying the respective ester of general formula (1) in which R1, R2, and R6 have the meanings indicated in the claims and the description. The method according to the invention allows the reaction to take place in very gentle basic conditions, causing fewer secondary reactions and providing a greater yield than reactions in highly polar aprotic solvents. Acid-sensitive and/or temperature-sensitive compounds can be synthesized.
摘要:
A process for preparing telmisartan by reacting 2-n-propyl-4-methyl-6-(1′-methylbenzimidazol-2′-yl)benzimidazole with a compound of formula (IV) wherein Z is a leaving group, to obtain the compound 2-cyano-4′-[2″-n-propyl-4″-methyl-6″-(1′″-methylbenzimidazol-2′″-yl)benzimidazol-1″-ylmethyl]biphenyl, and subsequently hydrolyzing the nitrile function to obtain the acid function.
摘要:
A process for preparing 1,7′-dimethyl-2′-propyl-2,5′-bi-1H-benzimidazole of formula (I) reacting N-methyl-o-phenylenediamine of formula (II) or the salts thereof with 2-propyl-4-methyl-1H-benzimidazole-6-carboxylic acid of formula (III) or the salts thereof wherein the coupling and cyclization is achieved using 1,3,5-triazine and tertiary amine.
摘要:
A process for preparing epinastine hydrochloride of formula (I) the process comprising: (a) suspending and dissolving an epinastine base of formula (II) in water by the addition of aqueous hydrochloric acid at a pH of ≧7; (b) extracting the aqueous solution obtained from step (a) with an organic, water-immiscible solvent; (c) removing the organic, water-immiscible solvent from the aqueous solution obtained from step (b); and (d) adjusting the pH of the aqueous solution of step (c) to ≦6 using hydrochloric acid to precipitate the product of formula (I), and then drying the product.
摘要:
A process for preparing telmisartan by reacting 2-n-propyl-4-methyl-6-(1′-methylbenzimidazol-2′-yl)benzimidazole with a compound of formula (IV) wherein Z is a leaving group, to obtain the compound 2-cyano-4′-[2″-n-propyl-4″-methyl-6″-(1′″-methylbenzimidazol-2′″-yl)benzimidazol-1″-ylmethyl]biphenyl, and subsequently hydrolyzing the nitrile function to obtain the acid function.
摘要:
The present invention relates to an improved process for preparing 1,3-dimethyl-4,5-diaminouracil by catalytic reduction of 1,3-dimethyl-4-amino-5-nitrosouracil in the presence of a palladium/charcoal catalyst.