摘要:
The present invention relates to a process for the preparation of R- and S-lipoic acid and R- and S-dihydrolipoic acid comprising(a) reaction of where MS is SO2—R′ and R and R′ independently of one another are C1–C6-alkyl, C3–C8-cycloalkyl, C3–C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in methanol. The invention especially relates to processes for preparing pure R- or S-dihydrolipoic acid, which is either used directly or processed further to give R- and S-lipoic acid. The process also serves for the production of pharmaceuticals. The present invention further relates to a solution of sodium sulfide trihydrate and sulfur in methanol, the sulfur being present in a molar excess over the sodium sulfide trihydrate, and a kit which comprises the solution according to the invention.
摘要:
A process for reducing the phosphate content in waste water from the preparation of salts of ascorbic acid 2-monophosphate comprisesA. treating the waste water from the crystallization of the metal salts of ascorbic acid 2-monophosphate with an alkali metal or alkaline earth metal hypochlorite, chlorine or H.sub.2 O.sub.2,andB. precipitating, at a pH of 9-12, the inorganic phosphate which has been produced from organically bound phosphorus and/or was present in the waste water, especially as calcium phosphate.
摘要翻译:从制备抗坏血酸2-单磷酸盐的盐中降低废水中的磷酸盐含量的方法包括:用碱金属或碱土金属次氯酸盐对2-一磷酸抗坏血酸的金属盐进行结晶处理废水 ,氯或H 2 O 2,和B.在pH为9-12的条件下沉淀出由有机结合的磷生成的和/或存在于废水中,特别是作为磷酸钙的无机磷酸盐。
摘要:
A process for preparing 9-(Z)-retinoic acid from mother liquors from the industrial preparation of C.sub.15 -triarylphosphonium salts of the general formula I ##STR1## where R.sup.1 to R.sup.3 are each aryl and X.sup..crclbar. is halogen or (HSO.sub.4).sup..crclbar., in an organic solvent, which comprisesA. increasing the proportion of 9-(Z)-C.sub.15 -triarylphosphonium salt in the C.sub.15 -triarylphosphonium salts isolated from the mother liquor by treatment with isopropanol at elevated temperature, cooling and separating off the all-(E)-C.sub.15 -triarylphosphonium salt which has crystallized out,B. subjecting the resulting C.sub.15 -triarylphosphonium salt to a Wittig reaction with an alkyl .beta.-formylcrotonate of the general formula ##STR2## and C. hydrolyzing the resulting oily retinoic ester mixture in a C.sub.3 -C.sub.9 -alkanol, preferably in a propanol or butanol, precipitating the resulting 9-(Z)-retinoic acid where appropriate by adding methanol as crystals, with all-(E)-retinoic acid and other retinoic acid isomers remaining in the alkanolic solution.
摘要:
13-(Z)-Retinoic acid is prepared bya) reacting 5-hydroxy-4-methyl-2(5H)-furanone with a [3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4-pentadienyl]triarylphosphonium salt andb) subsequently partially isomerizing the resulting mixture of 13-(Z)- and 11,13-di-(Z)-retinoic acid,where the reaction in step a) is carried out in the presence of lithium hydroxide as alkali metal hydroxide and in dimethylformamide as solvent at from +10.degree. to -9.degree. C. and/or the isomerization in step b) is carried out by irradiating the mixture of isomers obtained in a) in an organic solvent in the presence of a photosensitizer with light in the wavelength range from 200 to 600 nm.
摘要:
An improved process for preparing E,Z-butenedial bis(dialkyl acetals) by reacting the corresponding 2,5-dialkoxy-2,5-dihydrofurans with the corresponding lower alkanols in the presence of an acid at elevated temperature entails carrying out the reaction in the presence of approximately equimolar amounts of a trialkyl orthoformate and in the presence of catalytic amounts of a strong mineral acid or of a strong organic acid.
摘要:
Ascorbic acid 2-phosphate is prepared by reacting ascorbic acid or an ascorbic acid derivative with POCl.sub.3 in the presence of a tertiary amine in a suitable aqueous solvent at from -10.degree. to 25.degree. C. while maintaining a pH of about 8-13.5 with KOH during the entire phosphorylation reaction and then isolating the ascorbic acid 2-phosphate, by a process in which an aqueous solution of a magnesium compound is added to the reaction mixture obtained in the phosphorylation, without prior treatment with an ion exchanger, until the formation of crystalline KMg PO.sub.4 is complete, the KMgPO.sub.4 which is crystallized out is separated off, the resulting filtrate is evaporated down at a pH of from 6 to 11 and/or from 0.1 to 5 times the amount, based on the evaporated filtrate, of a lower primary alkanol or acetone is added and the stirred mixture is cooled until KCl has completely crystallized out, and the ascorbic acid phosphate is isolated in a conventional manner from the reaction solution obtained by separating off KCl and substantially freed from inorganic salts. It is particularly advantageous if the ascorbic acid 2-phosphate is isolated in the form of the novel potassium magnesium ascorbate 2-phosphate, which is also claimed.The process is particularly advantageous if the ascorbic acid derivative used is 5,6-isopropylideneascorbic acid which has been obtained by reacting ascorbic acid with acetone in the presence of oleum. The process is particularly important for the preparation of L-ascorbic acid 2-phosphate.
摘要:
The invention relates to intermediate compounds having the general formula I ##STR1## in which R.sup.1 is H, an alkyl, arylalkyl or an aliphatic acyl radical, preferably a benzyl or acetyl group and wherein X and Y together span an additional bond between the X and Y carrying C atoms (Ia) or in which Y is OH and X is H (Ib) and in which the dotted line can represent an additional bond particularly [2R,1'Z,3'E,7'E]-6-benzyloxy-2,5,7,8-tetramethyl-2-(4',8',12'-trimethyl-trideca-1',3',7'-trien-1'-yl)chroman and 6-benzyloxy-2,5,7,8-tetramethyl-2-(1'-hydroxy-4',8',12'-trimethyl-trideca-3',7'-diene-1'-yl)chroman, as well as compounds and methods of preparing compounds having the general formula II ##STR2## in which Z is one of the groups ##STR3## wherein R.sup.2 is an alkyl group with 1 to 4 carbon atoms preferably CH.sub.3 or C.sub.2 H.sub.5, particularly (3,7,11-trimethyl-trideca-2,6,10-trien-1-yl)triphenylphosphonium chloride and (3,7,11-trimethyl-trideca-2,6,10-trien-1-yl) phosphoric acid dimethylester as well as methods for the preparation of (2R,4'RS,8'RS)-.alpha.-tocopherol and (all-rac)-.alpha.-tocopherol via the new intermediate product.
摘要:
New acetals, containing a 6-membered ring, of 2-methyl-2,4-dialkoxy-3-buten-1-al, are obtained by reacting the corresponding 2-methyl-2-alkoxy-3-butyn-1-al-acetals with a mixture of the appropriate alcohol and an alkali metal alcoholate of the said alcohol at from 100.degree. to 200.degree. C. The acetals are intermediates for the preparation of carotinoid-based physiologically safe food dyes.
摘要:
The present invention relates to a process for the preparation of R— and S-lipoic acid and R— and S-dihydrolipoic acid comprising (a) reaction of where MS is SO2—R′ and R and R′ independently of one another are C1-C6-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in methanol. The invention especially relates to processes for preparing pure R— or S-dihydrolipoic acid, which is either used directly or processed further to give R— and S-lipoic acid. The process also serves for the production of pharmaceuticals. The present invention further relates to a solution of sodium sulfide trihydrate and sulfur in methanol, the sulfur being present in a molar excess over the sodium sulfide trihydrate, and a kit which comprises the solution according to the invention.
摘要:
A process for preparing folic acid, which comprises reacting a tetraalkoxypropanol of the general formula I, in which the substituents R are C1-C4-alkyl, with triaminopyrimidone of the formula II and p-aminobenzoyl-L-glutamic acid of the formula III