6-hydroxy-pyridoxine

Pyridoxin-Hydrochlorid kann in In Salzsaurc selektiv an der 4-Hydroxymethyl -Gruppe zum 3-Hydroxy-2,4-dimethyl-5-hydroxymethyl-pyridin (—99% d.Th.) reduziert werden (vgl. a. S.604)4 ... 

The steroids aldosterone, cortisone, cortisol, 11-P-hydroxyandrostenedione, corticosterone, and rostenedione, 11-desoxycorticosterone, 17-hydroxy-progesterone, and progesterone have been performed on Ultrasphere ODS using methanokwater.19 Ranitidine N-[2-[[[5-[(dimethylamino)methyl]-2-furanyl]-methyl]thio]ethyl]-N1-methyl-2-nitro-l,l-ethenediamine has been separated using a p-Bondapak C18 column operated with acetoni-trile methanol water buffered with triethylamine phosphate.117 Pyridoxal-5 -phosphate and other B6 vitamers, including pyridoxamine phosphate, pyri-doxal, pyridoxine, and 4-pyridoxic acid, were separated as bisulfite adducts... 

Phenomenex (see 2006 Catalog, SPE products) Strata-X Polar functionalized styrene-divinylbenzene polymer Reversed phase with weakly acidic, hydrogen bond donor, acceptor, and dipolar interactions Cetirizine (76) pyridoxine (77) omeprazole (78) mycophenolic acid (79) 25-hydroxy-vitamin D3 (80)... 

Alkyl-substituted oxazoles have been found to react with maleic acid or its anhydride in a diene synthesis to yield substituted pyridine readily converted to pyridoxine (39). In this route, ethyl d, 1-alaninate hydrochloride is treated with formic-acetic anhydride to yield ethyl N-formyl d,1-alaninate (78%). This compound is refluxed in chloroform with phosphorous pentoxide (40), quenched with aqueous potassium hydroxide, and the organic layer distilled to give 4-methyl-5-ethoxyoxazole (I) (60%). The resulting oxazole (I) is condensed readily with a number of appropriate dienophiles to form 2-methyl-3-hydroxy-4,5-disubstituted-pyridines containing substituents (III, a, b, c) which could be converted to pyridoxine as follows ... 

A mixture of the oxazole (I) with two moles of diethyl maleate (Ila) is heated and the adduct cleaved with ethanolic hydrogen chloride to form the diethyl ester of 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylic acid hydrochloride (Ilia) (85%). This diester is reduced with lithium aluminum hydride to pyridoxine (41-42) isolated as its hydrochloride. 

A solution of the oxazole (I) in a 20-mole excess of 2,5-dihydrofuran (lie) containing 1% of trichloroacetic acid is heated to give 2-methyl-3-hydroxy-4,5-epoxy-dimethylpyridine (IIIc) of 95% purity (58%). The cyclic ether (IIIc) is cleaved with 48% hydrobromic acid to the dibromide hydrobromide (III, Y=CH2Br) and hydrolysed to pyridoxine (35-36). 

The ether solution containing diethyl 2-methyl-3-hydroxy-pyridine-4,5-dicarboxylate is treated with 0.5 g of lithium aluminum hydride. The resulting mixture is stirred for 2 h and allowed to stand overnight. The ether layer is removed and the aqueous layer is saturated with carbon dioxide. The resulting residue is extracted three times with hot ethanol and gaseous HCI is passed into the ethanol extracts. After allowing the acidified ethanol solution to stand for 2-3 h, crystals of pyridoxine hydrochloride are deposited and recovered by filtration. Melting point 203.5°-205°C, dec. 

Be and for the biosynthesis of isoprenoids via the nonmeval-onate pathway. Condensation of 43 with 3-amino-l-hydroxy-acetone phosphate (47) (biosynthesized from D-erythrose 4-phosphate) affords pyridoxine 5 -phosphate (48, Fig. 5A). A sequence of elimination, tautomerization, and water addition precedes cyclization via an aldol condensation (26, 27). Then, pyridoxine 5 -phosphate can be converted into pyridoxal 5 -phosphate (39) by oxidation with molecular oxygen. 

Pyridoxine Hydrochloride, USP. Pyridoxine hydrochloride.. S-hydroxy-6-methyl-3.4-pyridinedimethanol hydrochloride. vitamin B, hydrochloride, rat antidermatitis factor. is a white, odorless, crystalline substance that is soluble l .S in water and 1 100 in alcohol and in.soluble in ether. It is relatively. stable to light and air in the solid form and in acid solutions at a pH no greater than S. at which pH it can be autoclaved at IS pounds at I20°C for 20 to 30 minutes. Pyridoxine is unstable when irradiated in aqueous solution.s at pH 6.8 or above. It is oxidized readily by hydrogen peroxide and other oxidizing agents. Pyridoxine is as stable in mixed vitamin preparations as riboflavin and nicotinic acid. A 1% aqueous solution has a pH of 3. The pK i values fur pyridoxine. pyridoxal. and pyridoxamine are S.OO. 4.22. and 3.40. respectively, and their pK 2 values are 8.96. 8.68. and 8.05. respectively. 

Chemical Name Pyridoxine Chemical Abstracts Services Registry Numbers CAS 58-56-0 CAS 65-23-6 Synonyms Vitamin Pyridoxal Pyridoxamine Adermine hydrochloride 3,4-Pyridinedimethanol 5-Hydroxy-6-methyl hydrochloride Chemical/Pharmaceutical/Other Class Water-soluble vitamin... 

Vitamers are chemically similar substances that have a qualitatively similar vitamin activity. Thus, vitamin D refers to ergocalciferol (Da) and cholecalciferol (D3) and sometimes to their 25-hydroxy- and 1,25-dihydroxy derivatives (Chapter 37). Similarly, pyridoxine (pyri-doxol), pyridoxal, and pyridoxamine are vitamin Be vitamers, riboflavin is the active form of vitamin Ba and cobalamin is vitamin Bia- The members of a particular vitamin family are functionally interchangeable and protect against deficiency symptoms for that vitamin. A vitamin and its corresponding deficiency disease are related as follows ... 

Quinone methides are frequently reported as intermediates from irradiation of arenes having a methyl or substituted methyl group in the 2-position to a carbonyl or nitro group (H-abstraction) or a hydroxy function (formal loss of water). The latter process has been studied with pyridoxine (201) and its derivatives (202) and (203), and the mechanism by which the loss occurs is found to depend upon the pH of the solution. In neutral solution, the formation of the quinone methide (204) from (201) arises either by excited state proton transfer to the aqueous methanol solvent and loss of OH from the phenoxide ion, or by intramolecular proton transfer and loss of water, while the reaction in alkaline solution involves dehydroxylation from the excited state of the phenoxide ion. 

Most of the work reported on the thienol3,4-c]pyridine system has been concerned with the preparation of substances related to pyridoxine and pyridoxal. Kreisky69 claimed to have obtained 4-hydroxy-5-methyl-... 

The infrared (IR) data quoted for 5-hydroxythieno[2,3-6]pyridinel (the isostere of 3-hydroxyisoquinoline) implies no contribution from the keto tautomer, and in numerous reports on studies of pyridoxine-type analogs,69, 11-73,92-94 which contain a 7-hydroxy-thieno[3,4-c]pyridine system, the oxygen function /3 to the nitrogen is invariably represented as a normal hydroxy group. In a paper devoted to ketoenol equilibria in l,3-dihydro-5-hydroxythieno[3,2-6 pyridine derivatives42 (72-73), it was reported that the keto farms were exclusively present in the solid state, but in dioxane the ratios 72 73 and 74 75 were 0.43 1 and 1.09 1, respectively. These facts were interpreted in terms of steric and electronic effects. 

Merck) Chem. Zentr. 1941, II, 2353 van Wagtendonk, Wibaut, Rec. Trav. Chim. 61, 728 (1942) from S-acetoxy-3-cyano-2-hydrOxy-4,6-dimethylpyridine which on treatment with FQS gives rhe 2-chlorO analog which on catalytic hydrogenation, diazotization. and hydrolysis gives 4-desoxy-pyridoxine Coover, Bowman, U.S. pat. 2,481,573 (1949 to Merck Co.) the quickest and best prepn is by caralytic reduction of pyridoxine Harris, J. Am. Chem. Soc. 62, 3203 (1940). Inhibits vitamin B6 in chick, rat, mouse, dog, monkey, and man. Readily produces symptoms of vitamin B( deficiency Mueller, Vilter, J. Ciin. Invest. 29, 193 (1950). 

Pyridoxic Acid, 3-Hydroxy-5-(hydroxymethyl)-2-meihyl-4-pyridinecar boxy lie acid 3-hydroxy-5-(hydroxy-methyl)-2-methylisonicotinic acid 2 -methyl-3 -hydroxy -4-carboxy-5-hydroxymethylpyridine. CgHjNO, mol wt 183,16. C 52.46%, H 4.95%, N 7.65%, O 34.94%. Occurs in urine. It is the chief metabolic product of pyridoxine pyridoxal, and pyridoxamine. Isoln from human urine Singal, Sydenstricker, Science 78, 545 (1941). Isoln and synthesis Huff, Perlzweig, J. Biol Chem ]S5, 345 (1944). 

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