cas 2124-57-4, Vitamin K2(35) | Articles data

Articles about 2124-57-4Total 8 be found

PROCESS OF VITAMIN K2 DERIVATIVES PREPARATION
The invention relates to an improved process of vitamin K2 derivatives preparation via the alkylation of the menadione-cyclopentadiene adduct.
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(2021/04/17)

Menaquinol Compositions and Methods of Treatment
The present application discloses methods for the efficient preparation of high purity compounds of the Formula I, and their methods of use.
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(2020/04/09)

PROCESS OF VITAMIN K2 DERIVATIVES PREPARATION
Provided is an improved process of vitamin K2 derivatives preparation, represented by formula (I) wherein n is an integer from 3 to 13.
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(2019/10/29)

Convergent Synthesis of Menaquinone-7 (MK-7)
A practical synthesis of menaquinone-7 (MK-7, Vitamin K2) in the all-trans form was designed. Stereoselective synthesis of MK-7 was achieved through a "1 + 6" convergent strategy by condensation of two building blocks, menadione monoprenyl derivative (fragment "1") with hexaprenyl bromide (fragment "6", 82%). Pd-catalyzed desulfonation with LiEt3BH (78%) was followed by oxidation of the hydroquinone moiety using ammonium cerium(IV) nitrate (72%). The major challenge in our methodology was the preparation of all-trans hexaprenyl bromide by coupling of two triprenyl units derived from trans, trans-farnesol. Manufacturing on a pilot scale was accomplished through our approach. The scalable method was designed especially for a large, kilogram-scale production from easily available intermediates. Furthermore, the proposed methodology avoids many chromatographic purifications and allows for a relatively cost-effective manufacturing. Moreover, our synthesis yielded high-purity (99.9%) final product MK-7, which can be used as a dietary supplement as well as an active pharmaceutical ingredient.
Baj, Aneta,Wa?ejko, Piotr,Kutner, Andrzej,Kaczmarek, ?ukasz,Morzycki, Jacek W.,Witkowski, Stanis?aw
p. 1026 - 1033
(2016/11/11)

Convergent synthesis of menaquinone-7 (MK-7)
A practical synthesis of menaquinone-7 (MK-7, vitamin K2) in the all-Trans form was designed. Stereoselective synthesis of MK-7 was achieved through a "1 + 6" convergent strategy by condensation of two building blocks, menadione monoprenyl derivative (fragment "1") with hexaprenyl bromide (fragment "6", 82%). Pd-catalyzed desulfonation with LiEt3BH (78%) was followed by oxidation of the hydroquinone moiety using ammonium cerium(IV) nitrate (72%). The major challenge in our methodology was the preparation of all-Trans hexaprenyl bromide by coupling of two triprenyl units derived from trans,trans-farnesol. Manufacturing on a pilot scale was accomplished through our approach. The scalable method was designed especially for a large, kilogram-scale production from easily available intermediates. Furthermore, the proposed methodology avoids many chromatographic purifications and allows for a relatively cost-effective manufacturing. Moreover, our synthesis yielded high-purity (99.9%) final product MK-7, which can be used as a dietary supplement as well as an active pharmaceutical ingredient.
Baj, Aneta,Wa?ejko, Piotr,Kutner, Andrzej,Kaczmarek, L?ukasz,Morzycki, Jacek W,Witkowski, Stanisl?aw
p. 1026 - 1033
(2017/01/16)

Method of preparation of stereospecific quinone derivatives
A novel process for the regio- and stereospecific synthesis of polyprenylated quinone derivatives, such as Vitamin K1, K2 and Ubiquinone, has been achieved exploiting dithioacetal-, especially 1,3-dithiane-, mediated Umpolung chemistry which works along a new concept "Inhibiting resonance delocalization (IRD)" to overcome isomerization generated due to delocalization of allylic carbanions on the π-electron cloud of an allylic system. The present novel synthesis of all-trans Vitamins K1, K2 and Ubiquinone is achieved by coupling of a quinone group with a polyprenyl side chain where either of the two moieties may have 1,3-dithiane as a terminal group while undergoing umpolung chemistry. Similarly while coupling two polyprenyl fragments to each other in building of the all-trans side chain. A stereospecific synthesis of vitamin K1 was also achieved along the same synthetic outline using a chiral hexahydrofarnesyl derivative retaining optical and geometrical isomeric properties equivalent to those of the natural K1.
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(2015/05/19)

METHOD OF PREPARATION OF STEREOSPECIFIC QUINONE DERIVATIVES
The description provides processes for the regio and stereospecific synthesis of polyprenylatedquinone derivatives, such as Vitamin K1, K2 and Ubiquinone, exploiting dithioacetals, especially 1,3-dithiane, mediated Umpolung chemistry which works along a new concept “Inhibiting resonance delocalization (IRD)” to overcome isomerization generated due to delocalization of allyliccarbanion on the π-electron cloud of an allylic systems by the conventional synthesis.
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(2015/05/13)

PROCESS FOR PREPARATION OF MK-7 TYPE OF VITAMIN K2
Process for preparation of MK-7 type of vitamin K2 is characterized by attaching hexaprenyl chain of ?all-trans" configuration to monoprenyl derivative of menadiol following ?1 + 6" synthetic strategy. According to the invention, a-sulfonyl carbanion generated in situ from the protected monoprenyl menadiol of the formula (II), wherein R1 represents C1-3-alkyl group, is reacted with hexaprenyl halide of the formula (VII), wherein X represents halogen atom, preferably bromine, both Z' and Z' represent H or one of Z' and Z" represents H and the other represents phenylsulfonyl group -SO2Ph in the alkylation reaction. The hexaprenyl halide of formula (VII) is obtained by coupling two triprenyl units in alkylation reaction, with or without separation of the intermediates.
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(2014/05/07)