摘要:
Riboflavin produced by a microbial method is prepared in the form of free-flowing, non-dusting, spray-dried granules or microgranules as a feed additive by removing water from the mixture discharged from microbial fermentation for the preparation of riboflavin, wherein the mixture is subjected to(a) a fluidized-bed spray-drying process(b) a one-material spray-drying process or(c) a disk spray-drying process without significant amounts of binders being added to the discharged fermentation mixture.
摘要:
A method of purifying ferment-produced riboflavin, wherein the impure riboflavin is suspended in water or dilute aqueous acid, and the suspension is heated at a temperature of from 75.degree. to 130.degree. C. for from 0.3 to 3 hours with stirring, during which time crystal transformation takes place, after which the mixture is cooled and the purified product is isolated in known manner.
摘要:
A process for preparing spray granules or microgranules, which contain no binder, are non-dusting and free-flowing, from finely divided pure riboflavin, comprises subjecting an aqueous or water-containing suspension of the pure finely divided riboflavin toa) a fluidized bed spray dryingb) a single-nozzle spray drying orc) a disk-type spray dryingin particular a fluidized bed spray drying, without adding binders to the suspension, and the spray granules or microgranules of riboflavin obtainable by this process.
摘要:
Riboflavin is removed from fermentation suspensions by them being heated at from 50.degree. to 90.degree. C. for from 1 to 3 hours, than cooled to from 0.degree. to 30.degree. C. over a period of from 1 to 5 hours, and subsequently being centrifuged to give a sediment fraction and liquid fraction in such a way that the sediment fraction contains predominantly riboflavin crystals as solid, and the liquid fraction contains virtually no crystalline riboflavin, and, where appropriate, resuspending the sediment fraction in from 0.5 to 2 parts by volume of water per part by volume of sediment fraction and repeating procedure c.
摘要:
Riboflavin-4',5'-cyclophosphoric acid chloride of the formula I ##STR1## its preparation by reacting an alkali metal salt of riboflavin, in an aprotic solvent, with phosphorus oxychloride, its use for the preparation of riboflavin-5'-phosphate and of the sodium salt of riboflavin-5'-phosphate, and a process for the preparation of riboflavin-5'-phosphate or its sodium salt via the novel phosphoric acid ester chloride.
摘要:
An improved process for preparing riboflavin 5'-phosphate (FMN) or its monosodium salt by reacting riboflavin with excess phosphorus oxychloride in a solvent, hydrolyzing of the resulting reaction mixture and, if desired, partially neutralizing with aqueous sodium hydroxide solution, comprises reacting the riboflavin with from 1.2 to 3 moles of phosphorus oxychloride per mole of riboflavin in a suitable lactone, especially .gamma.-butyrolactone, as solvent. The process is particularly advantageous when the reaction mixture is hydrolyzed at from 80.degree. to 90.degree. C. continuously or batchwise.
摘要:
A process for the stereoselective preparation of (-)3a,6,6,9a-tetramethylperhydronaphtho[2,1-b]furan of the formula Ia ##STR1## by dehydration and cyclization of decahydro-2-hydroxy- 2,5,5,8-tetramethyl-1-naphthaleneethanol using solid acidic catalysts, wherein the decahydro-2-hydroxy- 2,5,5,8-tetramethyl-1-naphthaleneethanol is heated in the molten state at from 80.degree. to 200.degree. C. in the presence of from 10 to 100% by weight, based on the diol, of an active acidic aluminum oxide commercially supplied for (preparative) column chromatography.
摘要:
Anthranilic acid amides are prepared by mixing phthalamic acid with a caustic alkali solution, a catalyst and a hypohalite, allowing the mixture to stand for from 1 to 1,000 seconds, then introducing the amine and thereafter addig acid until the pH of the mixture is from 6 to 8.The anthranilic acid amides obtainable by the process of the invention are valuable starting materials for the preparation of dyes, scents and pesticides.
摘要:
The present invention relates to a method for preparing cyclohexene derivatives of the general formulae I or II by reducing alkyne compounds of the general formulae III or IV with a mixture of zinc and at least one ammonium salt of the formula V as reducing agent, in which the substituents R1 to R8 have independently of one another the meaning specified in the description, wherein the reducing agent comprises from 0.3 to 0.49 mol of at least one ammonium salt of the formula V per mol of zinc.
摘要:
Riboflavin of the formula I ##STR1## is prepared by an improved process by condensing a 4,5-dimethyl-N-(D)-ribityl-2-phenylazoaniline of the formula II ##STR2## where R is H, --CL, --NO.sub.2, --CH.sub.3 or --OCH.sub.3 in the o- or p-position, with barbituric acid of the formula III ##STR3## in the presence of an acid as a condensing agent, by a process in which the acidic condensing agent used is an aliphatic secondary carboxylic acid of the general formula IV ##STR4## where R.sup.1 is methyl or ethyl and R.sup.2 is alkyl of 3 or 4 carbon atoms.