NZ716277B2

NZ716277B2 - Methods of preparing nicotinamide riboside and derivatives thereof

Info

Publication number: NZ716277B2
Application number: NZ716277A
Authority: NZ
Inventors: Kerri Crossey; Mark Doherty; Marie Migaud; Philip Redpath
Original assignee: The Queen's University Of Belfast
Priority date: 2013-07-29
Filing date: 2014-07-24
Publication date: 2021-06-29

Abstract

The invention relates to methods of preparing nicotinamide riboside and derivatives thereof. In an aspect, the invention relates to a method of preparing a compound of formula (I), wherein n is 0 or 1; m is 0 or 1; Y is O or S; R1 is selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted primary or secondary amino, and substituted or unsubstituted azido; R2- R5, which may be the same or different, are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, and substituted or unsubstituted aryl; and X- is an anion, selected from an anion of a substituted or unsubstituted carboxylic acid, a halide, a substituted or unsubstituted sulfonate, a substituted or unsubstituted phosphate, a substituted or unsubstituted sulfate, a substituted or unsubstituted carbonate, and a substituted or unsubstituted carbamate. r unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted primary or secondary amino, and substituted or unsubstituted azido; R2- R5, which may be the same or different, are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, and substituted or unsubstituted aryl; and X- is an anion, selected from an anion of a substituted or unsubstituted carboxylic acid, a halide, a substituted or unsubstituted sulfonate, a substituted or unsubstituted phosphate, a substituted or unsubstituted sulfate, a substituted or unsubstituted carbonate, and a substituted or unsubstituted carbamate.

Description

Methods of ing namide riboside and derivatives thereof Field of the invention The invention relates to methods of ing nicotinamide riboside and derivatives thereof.

Background to the invention Nicotinamide riboside and derivatives thereof, including nicotinate riboside, nicotinamide mononucieotide and nicotinate mononucleotide, are metabolites of nicotinamide adenine dinucleotide (NAD*). The B-anomer forms of nicotinamide riboside, nicotinate riboside, namide mononucleotide and nicotinate mononucleotide are shown, without counter ions, in Figure 1. As a NAD+ precursor, nicotinamide riboside has been shown in mice to enhance oxidative metabolism and protect against at diet induced obesity, which has resulted in cant interest in namide de and its derivatives. Since nicotinamide riboside is a naturally occurring compound, nicotinamide riboside and its derivatives have great potential as natural, ional supplements, which may provide health benefits t causing side effects. One limitation in the commercial exploitation of nicotinamide riboside and derivatives thereof, as nutritional supplements, or otherwise, is that known synthetic protocols for preparing nicotinamide riboside and derivatives thereof have disadvantages, rendering them unsuitable for scaling up for commercial or industrial use. describes a method for the preparation of nicotinamide riboside and derivatives f. However, the disclosed method has a number of disadvantages. For example, trimethylsilyl triﬂuoromethanesuifonate (TMSOTf) is used as the st in the disclosed method, and results in the prepared compounds inevitably being in the form of their triflate (‘OTf) salts. The triflate salt form of nicotinamide riboside, or derivatives thereof, is not suitable for use as a nutritional supplement, because of its associated toxicity. Thus, the compounds produced by the disclosed method are not le for use as they are prepared, and require an additional step to ge the triflate anion for an anion that would be pharmaceutically acceptable and therefore suitable for cialisation, utilizing for example, reverse phase liquid tography as sed. Additionally, nicotinamide riboside is chemically labile, in particular under the chromatographic conditions used in the disclosed method. it is therefore proposed that the chromatographic conditions used could result in s of less than optimum purity and, within the batches, great variability in terms of the side products produced. Another disadvantage is that careful control of the temperature of the reaction is necessary to minimise decomposition in the final stages of the synthesis of nicotinamide riboside, yet the disclosed method is exothermic and is therefore prone to nvironment thermal fluctuation, especially in the event of large scale production set up.

Tanimori at al (8. Tanimori, T. Ohta and M. Kirihata, Bioorganic & Medicinal try Letters, 2002, 12, 1135—1137) and etti et 8/ (P. Franchetti, M. Pasqualini, R. Petrelli, M. Ricciutelli, P. Vita and L. lacci, Bioorganic & Medicinal Chemistry Letters, 2004, 14, 658) also describe methods for the preparation of nicotinamide riboside. r, these methods also have the disadvantage of inevitably resulting in the preparation of the triflate salt by virtue of using TMSOTf as catalyst. in summary, the disclosed methods have disadvantages which present obstacles to the scaling up of the method for commercial or industrial use, and which, ore, greatly limit the commercial opportunities for the methods and the resultant compounds. it is therefore an object of the invention to avoid or mitigate the disadvantages of the prior art.

It is also an object of the invention to provide a novel, useful and efficient method for the preparation of nicotinamide riboside and derivatives f. it is also an object of the invention to provide a method for the ation of nicotinamide riboside and derivatives thereof, whereby the method may be used to introduce a counter ion of choice to the prepared compounds, thereby producing compounds suitable for use as nutritional supplements or otherwise.

Summary of the invention According to the present invention, there is provided a method of preparing a compound of formula (3) wherein nisOort; misOorl; YisOorS; R1 is selected from H, substituted or unsubstituted alkyi, substituted or unsubstituted i, substituted or unsubstituted alkynyi, substituted or unsubstituted aryl, substituted or unsubstituted primary or secondary amino, and substituted or unsubstituted azido; R2— R5, which may be the same or different, are each independently selected from H, substituted or unsubstituted alkyi, substituted or tituted aikenyi, substituted or unsubstituted aikynyl, and substituted or unsubstituted aryl; and X‘ is an anion, ed from an anion of a substituted or unsubstituted carboxyiic acid, a halide, a substituted or unsubstituted sulfonate, a substituted or unsubstituted phosphate, a substituted or tituted sulfate, a substituted or unsubstituted carbonate, and a substituted or unsubstituted carbamate; sing reacting a compound of formula (it) wherein n, m, Y and R1— R5 are as defined above; with a compound of the formuia Z+X‘, n X' is as deﬁned above, and wherein Z+ is a N-containing cation; in the presence of an aqueous solution and a carbon—containing catalyst; to form the compound of formula (l).

Optionally, Z is selected from a substituted or unsubstituted ammonium, a substituted or unsubstituted pyridinium, a substituted or unsubstituted pyrrolidinium, a substituted or unsubstituted imidazolium and a substituted or tituted triazolium.

Optionally, Z+ is a substituted or unsubstituted um of the formula N+HR'R"R'“, wherein R‘, R" and R”, which may be the same or different, are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyt, and substituted or unsubstituted aryl. ally, Z+ is an unsubstituted ammonium of the formula NHJ.

Optionally, X‘ is an anion of a substituted or tituted carboxylic acid selected from an anion of a tuted or unsubstituted monocarboxylic acid and an anion of a substituted or unsubstituted dicarboxylic acid. ally, X‘ is an anion of a tuted monocarboxylic acid, further optionally an anion of a substituted propanoic acid or an anion of a substituted acetic acid. Optionally, X‘ is an anion of substituted propanoic acid, further optionally an anion of a hydroxy propanoic acid, still r optionally an anion of 2—hydroxypropanoic acid, being tactic acid, the anion of lactic acid being lactate. Optionally, X“ is an anion of a substituted acetic acid, being a substituted acetate, further optionally a trihaloacetate selected from trichloroacetate, tribromoacetate and trifluoroacetate. Still further optionally, the trihaloacetate is triftuoroacetate.

Optionally, X' is an anion of an unsubstituted monocarboxyiic acid ed from formic acid, acetic acid, propionic acid and butyric acid, being formate, acetate, propionate and butyrate, respectively.

Optionally, X' is an anion of a substituted or tituted amino~monocarboxyiic acid or an anion of a substituted or unsubstituted amino-dicarboxylic acid. Further optionally, X’ is an anion of an amino-dicarboxylic acid, optionally selected from glutamic acid and ic acid, being giutamate and aspartate, respectively.

Optionally, X' is an anion of ascorbic acid, being ascorbate.

Optionally, X‘ is a halide selected from de, bromide, ﬂuoride and iodide, further optionally chloride or bromide, 2014/065971 Optionally, X‘ is a substituted or unsubstituted suifonate. Further optionally, X‘ is a trihalomethanesulfonate ed from trifluoromethanesulfonate, tribromomethanesuifonate and trichloromethanesulfonate. Still further optionally, the trihalomethanesulfonate is trifluoromethanesulfonate.

Optionally, X‘ is a tuted or unsubstituted carbonate, further optionally hydrogen ate.

Optionally, X’ is selected from chloride, acetate, formate, triﬂuoroacetate, ascorbate, aspartate, glutamate and lactate. Further optionally, X‘ is selected from chloride, acetate, formate and 1O trifluoroacetate.

Optionally, the compound of the formula Z*X' is selected from ammonium chloride, ammonium acetate, ammonium formate, ammonium triﬂuoroacetate, ammonium ascorbate, ammonium aspartate, ammonium glutamate and ammonium e. Further optionally, the compound of the formula [X is seiected from ammonium chloride, ammonium acetate, ammonium formate and ammonium triﬂuoroacetate.

Optionally, the compound of formula (ll) and the carbon—containing catalystare present in a tive molar ratio of from about 10:1 to about 1:10, optionally from about 5:1 to about 1:5, further optionally from about 4:1 to about 1:4, still further optionally about 1:1 or 1:2 or 1:3 or 1:4. ie -containing catalysts include, but are not limited to, activated charcoal or graphite.

As used herein, the term "activated charcoal" is intended to mean a carbon containing material processed to be highly porous y increasing the surface area of the material. The term "activated charcoal” is intended to be synonymous with the term “activated carbon". The activated charcoal may be in the form of powders and/or ﬁbres and/or granules and/or pellets. ally, the activated al may act as a support for a metal. Suitable metals include, but are not limited to, transition metals. Suitable transition metals include, but are not limited to the platinum group metals, optionally selected from ruthenium, rhodium, palladium, osmium, m, and platinum, or a combination thereof.

Optionally, the aqueous solution consists essentially of water.

Optionally, the aqueous solution comprises, in addition to water, an organic solvent.

Suitable organic solvents include, but are not limited to, substituted or unsubstituted ethers, substituted or tituted esters, substituted or tituted s, substituted or unsubstituted aiiphatic or aromatic hydrocarbons, and combinations thereof.

Optionally, the organic solvent, when present, ses an ether selected from diethyi ether, methyl tert-butyl ether, ethyl tert—butyl ether, di-tert-butyi ether, diisopropyl ether, dimethoxymethane, 4O ydrofuran, 2-methyltetrahydrofuran, and tetrahydropyran, or a combination thereof.

Optionally, the organic solvent, when present, comprises an ester selected from methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, isobutyl acetate and n—butyl acetate, or a combination thereof.

Optionally, the organic solvent, when present, comprises a ketone selected from methyl isobutyl ketone and methyl isopropyl ketone, or a combination thereof.

Optionally, the c solvent, when present, comprises an unsubstituted tic hydrocarbon solvent ed from pentane, hexane, cyclohexane and e, or a combination thereof.

Optionally, the organic t, when present, comprises a substituted aliphatic hydrocarbon solvent, optionally a halogenated aliphatic hydrocarbon t, further optionally a chlorinated aliphatic 1O hydrocarbon sotvent selected from dichloromethane, trichloromethane, tetrachtoromethane, 1,2— chloroethane, 1, 1, 1-trichloroethane and trichloroethylene, or a combination thereof.

Optionally the c soivent, when present, comprises an aromatic hydrocarbon solvent selected from benzene, e, enzene and xylene, or a combination thereof. ally, the aqueous solution comprises water and organic solvent in a respective ratio by volume of from about 1:5 to about 5:1, optionally from about 1:3 to about 3:1, further optionally from about 1:2 to about 2:1, still further optionally about 1:1.

Optionally, the reaction is carried out in a pH range of from about 6 to about 8, optionaliy from about 6.5 to about 7.5.

Optionally, the reaction is carried out at a temperature of from about 10°C to about 40°C, optionally from about 15°C to about 35°C, further optionally from about 15°C to about 30°C, still further optionally from about 15°C to about 20°C, even further optionally from about 20°C to about 25°C, even r optionally at a ature of about 20°C or 21°C or 22°C or 23°C or 24°C or 25°C.

Optionally, the reaction is carried out for a period of time of from about 1 minute to about 180 minutes, optionally, from about 2 minutes to about 120 s, further optionally from about 5 minutes to about 120 minutes, stiil further optionally from about 10 minutes to about 120 minutes, even further optionally from about 20 minutes to about 120 s, even further optionally from about 30 s to about 120 minutes, stilt further optionally from about 60 minutes to about 120 minutes, even further optionaliy from about 60 minutes to about 90 minutes, stili further optionally about 60 minutes or 70 s or 80 s.

Optionally, the method further comprises a ﬁltration step to remove the carbon-containing catalyst from the prepared compound of formula (I). le ﬁltration means for use in the filtration step include, but are not limited to, syringe ﬁlters and/or paper ﬁlters, and/or any inert, insoluble substance capable of acting as a ﬁlter, e.g, alumina and/or silica and/or diatomaceous earth. it will be appreciated any other suitable filtration means may be used.

As used herein, the term “substituted” is intended to mean that any one or more hydrogen atoms is replaced with any suitable substituent, provided that the normal valency is not exceeded and the replacement results in a stable compound. Suitable substituents include, but are not limited to, alkyl, alkylaryl, aryl, heteroaryl, halide, hydroxyl, carboxylate, carbonyl (including alkylcarbonyl and arylcarbonyl), phosphate, amino (including alkylamino, dialkylamino, hydroxylamino, dihydroxylamino, alkyl hydroxylamino, arylamino, diarylamino and alkylarylamino), thiol (including alkylthiol, arylthiol and thiocarboxylate), sulfate, nitro, cyano and azido.

As used herein, the term “alkyl” is intended to mean a substituted or tituted, saturated or unsaturated, optionally saturated, linear, branched or cyclic, aliphatic hydrocarbon, having from 1 to 12 carbon atoms, optionally from 1 to 10 carbon atoms, r optionally from 1 to 8 carbon atoms, still further optionally from 1 to 6 carbon atoms, even still further optionally 1 or 2 or 3 or4 or 5 carbon atoms. Suitable alkyls include, but are not limited to, methyl, ethyl, n-propyl, opyl, n- butyl, iso-butyl, tert-butyl, yl, iso-pentyl, n-hexyl, iso-hexyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. Optionally, when Y is O, n is 1, and m is 1, ethyl is preferred.

As used herein, the term “alkenyl" is intended to mean a tuted or unsubstituted, linear, branched or cyclic, aliphatic hydrocarbon, having at least one -carbon double bond, and having from 2 to 12 carbon atoms, optionally from 2 to 10 carbon atoms, further optionally from 2 to 8 carbon atoms, still further ally from 2 to 6 carbon atoms, even still further ally 2 or 3 or 4 or 5 carbon atoms. Suitable alkenyl groups include, but are not limited to, ethenyi, propenyl and l, As used herein, the term “alkynyl” is ed to mean a substituted or unsubstituted, linear, branched or cyclic, aliphatic hydrocarbon, having at least one carbon-carbon triple bond, and having from 2 to 12 carbon atoms, optionally from 2 to 10 carbon atoms, further optionally from 2 to 8 carbon atoms, still further optionally from 2 to 6 carbon atoms, even still further optionally 2 or 3 or 4 or 5 carbon atoms. Suitable alkynyl groups e, but are not limited to, ethynyl, propynyl, butynyl, and the like.

As used herein, the term “aryl” is intended to mean a tuted, tituted, monocyclic or 3O polycyclic, aromatic hydrocarbon. le aryls include, but are not limited to, substituted or unsubstituted phenyl, and substituted or unsubstituted heteroaryl.

Optionally, the substituted or unsubstituted primary or secondary amino is ed from substituted or unsubstituted alkylamino, substituted or unsubstituted dialkylamino, substituted or unsubstituted hydroxylamino, substituted or unsubstituted dihydroxylamino, and substituted or unsubstituted alkyl hydroxylamino.

Optionally, the substituted or unsubstituted azido is selected from substituted or unsubstituted alkyl azido and substituted or unsubstituted aryi azido. it will be appreciated that, when n is 0 and m is 0, R1 is directly attached to the pyridine ring or to the pyridinium ring, as appropriate.

Optionally, in an embodiment of formula (l), n is O, m is 1, R1 is NHZ, R2 ~ R5 are each H, and X' is selected from chloride, acetate, formate and trifluoroacetate.

Optionally, in an embodiment of formula (ll), n is 0, m is 1, R1 is NH?” and R2 — R5 are each H.

Optionally, the compound of formula (II) and the compound of the formula Z+X‘ are present in a respective molar ratio of from about 1:5 to about 5:1, optionally from about 1:3 to about 3:1, further optionally from about 1:2 to about 2:1, still r optionally about 1:1. ally, the method comprises ng the reactants, optionally using a magnetic or ical stirrer, further optionally an overhead mechanical stirrer. ln an ment, the carbon-containing catalyst used in the preparation of a compound of a (l) may be provided in the form of an activated charcoal column, for example an activated charcoal material such as those supplied by Sigma Aldrich under the trade names NORlT (Trade Mark) or DARCO (Trade Mark), or from CarboChem, W Lancaster Ave, e, PA 19003, USA, or a carbon supported catalyst in a CatCart Packer (Trade Mark) column from ThalesNano, soft Park, Zéhony u. 7‘ H1031 Budapest, Hungary. in this embodiment, the activated charcoal column may be used as part of any suitable liquid chromatography , including, but not limited to, a fast protein liquid chromatography (FPLC) or a high performance liquid chromatography (HPLC) system, or a flow chemistry system, such as the ThalesNano (Trade Mark) H-cube systems and related flow reactors, available from ThalesNano, details provided above, in this case, the nts would be recirculated onto the column in a continuous manner until the compound of formula (ll) is no longer detected by UV at 340nm.

Optionally, the compound of formula (It) is prepared by reacting a compound of formula (lll) (ill) wherein n, m. Y and R1—- R5 are as defined above; and R5, R7 and R8, which may be the same or different, are each independently a hydroxyl—protecting group; with a deprotecting agent; to form the compound of formula (II) le R6, R7 and R8 moieties include, but are not limited to, ester-type protecting groups, ether- type protecting groups, and silyl—type protecting groups.

As used , the term “ester-type protecting group” is ed to mean a protecting group that forms an ester bond for the e of yl protection and which may be substituted or unsubstituted. Suitable ester—type ting groups include, but are not limited to, acetyl, propionyl, isopropionyl, benzoyl, and trihaloacetyl, optionally trifluoroacetyl or trichloroacetyl.

As used herein, the term “ether-type protecting group" is intended to mean a protecting group that forms an ether bond for the purpose of hydroxyl tion and which may be tuted or unsubstituted. Suitable type ting groups include, but are not limited to, benzyl, p- methoxybenzyl, methoxymethyl and allyl ethers.

As used herein, the term “silyl—type protecting group” refers to a protecting group that forms a silyloxy bond for the purpose of hydroxyl protection. Examples thereof from trimethylsiiyl, triethylsilyl, triisopropylsilyl, 2—(trimethylsilyl)eth0)Q/methyl, tyldimethylsilyl, tert—butyldiphenylsilyl and tetraisopropyldisilyl.

Optionally, the R5, R7 and R8 moieties are selected from substituted and unsubstituted acetyl, and substituted and unsubstituted benzoyl.

Optionally, at least two of R6, R7 and R5 are selected from unsubstituted acetyl or unsubstituted benzoyl.

Optionally the deprotecting agent is an acid or a base. Deprotection can also be achieved by catalytic hydrogenation (Pd/C; Hz) for the aromatic ether protecting groups and by ﬂuoride-catalysed chemistry (at. TBAF in THF) for all the silyl ethers. Optionally, when R5, R7 and R3 each comprise unsubstituted acetyl or unsubstituted benzoyl, the deprotecting agent is a base, optionally selected from NH3, Nazcog and NaOH. it will be appreciated by a skilled person that any other tional deprotecting agent may be used.

Optionally, the on is carried out in the presence of a protic or c solvent or a combination thereof.

Suitable protic solvents include, but are not limited to, water, substituted or unsubstituted alcohol, or a combination thereof. Suitable substituted alcohols include substituted or unsubstituted fluorinated alcohols. Suitable unsubstituted alcohols include methanol, ethanol and propanol, optionally methanol. le aprotic organic solvents include, but are not limited to, substituted or unsubstituted , substituted or unsubstituted esters, substituted or unsubstituted ketones, substituted or unsubstituted aliphatic or ic hydrocarbons, and combinations thereof, as deﬁned above.

Optionally, the reactants are subjected to mechanical grinding, further ally using a ball milling or planetary ball g machine.

Optionally, in an embodiment of formula (lll), n is O, m is 1, R1 is NHZ, R2 — R5 are each H, and R6 ~ R8 are each acetyl.

Further optionally, in another embodiment of formula (Ill), n is 1, Y is O, m is 1, R1 is ethyl, R2 —— R5 are each H, and R6 — R8 are each acetyl.

Still further optionally, in another embodiment of formula (Ill), n is O, m is 1, R1 is NH2, R2 —- R5 are each H, and R6 -— R8 are each benzoyl.

Optionally, the nd of formula (ill) is prepared by reacting a compound of formula (W) wherein n, m, Y, R1- R8 and X' are as defined above; with a reducing agent, an aqueous solution and an organic solvent to form a nd of formula (lll).

Optionally, X- is selected from ascorbate, glutamate, aspartate, lactate and acetate.

Suitable organic ts are as deﬁned above in respect of the preparation of a compound of formula (I) from formula (ll).

Optionally, when at least two of R6, R7 and R8 comprise tituted acetyl, the organic solvent is selected from dichloromethane, 1,2—chloroethane, n—butyl acetate, chloroform and ethyl acetate, or a combination thereof, further optionally ethyl acetate.

Optionally, when at least two of R2, R3 and R4 comprise unsubstituted benzoyl, the organic solvent is selected from oroethylene, carbon tetrachloride, diisopropyl ether, toluene, methyl tert—butyl ether, e and diethyl ether, or a combination thereof, r optionally diethyl ether.

Optionally, the reducing agent is selected from sodium dithionite or sodium borohydride.

Optionally, the method may comprise the simultaneous addition of the reducing agent, aqueous solution and organic solvent; or the sequential addition of the reducing agent, aqueous solution and organic t, in any order; or a combination thereof.

Optionally, the aqueous solution consists essentially of water.

It will be appreciated that, ally, the aqueous solution and the organic solvent form a bi-phasic solution sing an aqueous phase and an organic phase.

Optionally, the method comprises the additional steps of separating the organic phase from the aqueous phase; and extracting the compound of a (ill) from the c solvent 4o it will be appreciated by a skilled person that the hydroxyl protecting groups R5, R7 and R8, are required to be lipophilic to the extent that the reduced compound of formula (Ill), once prepared, migrates into the organic phase of the bi-phasic reaction medium formed by the aqueous solution (aqueous phase) and organic t (organic phase).

Optionally, the reactants are ted to mechanical grinding, further optionally using a ball mill or planetary ball milling machine.

Optionally, in an ment of formula (W), n is O, m is 1, R1 is NHZ, R2 —— R5 are each H, R6 — R8 are each acetyl, and X‘ is ‘OTf.

Further optionally, in another embodiment of formula (ill), n is 1, Y is O, m is 1, R1 is ethyl, R2 —— R5 are each H, R5 -— R3 are each acetyl, and X‘ is 'OTf.

Still further optionally, in another ment of a (Ill), n is 0, m is 1, R1 is NHZ, R2 —— R5 are each H, and R6 - R8 are each benzoyl, and X" is ‘OTf.

According to the invention, there are also provided compounds derivable from the methods disclosed herein. ingly to the invention, there is further provided a compound of formula (l) wherein n, m, Y, R1— R5 and X‘ are as deﬁned above.

Optionally, X' is selected from acetate, formate and trifluoroacetate.

Optionally, the compound of formula (i) has the formula (LA), is is the B-anomer, \“c 3”; HOS ’40 (1A) wherein n, m, Y, R1~ R5 and X‘are as deﬁned above.

Optionally, the compound of formula (II) has the formula (HA), le. is the B~anomer, \\\\\\ (llA) wherein n, m, Y and R1-R5 are as deﬁned above.

Optionally, the compound of formula (lll) has the formula , Le. is the B-anomer, R70\ (lllA) wherein n, m, Y and R1~ R8 are as deﬁned above. ally, the compound of formula (W) has the formula (lVA), i.e. is the B-anomer, YnR1 R70‘ (NA) wherein n, m, Y, R1~R8 and X' are as deﬁned above Advantages of the invention include, but are not limited to the following: (1) The preparation of compounds of formula (1) from compounds of formula (ll) provides an efﬁcient method of ucing a counter ion of choice for namide riboside and its derivatives Starting from a compound of formula (ii), e.g. reduced NRH, a desired counter ion may be introduced. Furthermore, even if the method starts by using compounds of formula (IV) in the form of the te salt, the methods of the invention enable the triflate anion to be exchanged during the method in a simple and efﬁcient manner, to a counter ion of choice. Thus, the disclosed methods conveniently enable the preparation of compounds having potential use as nutritional supplements or otherwise. (2) The invention provides stereoselective methods for the preparation of nicotinamide riboside and derivatives thereof, producing the desired B-anomer. This is in contrast, for example, to Tanimori et al, which is not stereoselective and produces significant s of the Cl— anomer, which is undesirable. onally, the methods of the invention are useful, efﬁcient, and can be easily scaled up for industry and cialisation, and provide for the minimisation of solvent use, puriﬁcation and reaction time. For example, the methods of the invention for preparing compounds of formula (i) from compounds of formula (it), are conveniently completed in less than 2 hours with quantitative yields. The methods for the preparation of compounds of formula (l) starting from compounds of formula (W) are also very efficient and e very good yields. The methods may iently be carried out at room temperature. (3) The s described herein are capable of preparing not just nicotinamide riboside but also a whole range of derivatives, which is not disclosed in either ri et a/ or Franchetti et al. The derivatives include not just derivatives of namide riboside but also the reduced form of nicotinamide riboside and derivatives thereof. Furthermore, although not described herein, a skilled person will appreciate that, starting from compounds of formula (ll), it is possible to easily access the phosphorylated parents of nicotinamide riboside and derivatives thereof, for example nicotinamide cleotide and nicotinate mononucleotide. (4) The protecting groups used in the preparation of compounds of a (ill) from compounds of formula (W) may advantageously be chosen to be sufﬁciently lipophilic so that they facilitate the migration of the compounds of formula (lll) into the organic phase of the reaction medium, for ease of extraction. (5) The methods described herein conveniently use nts which enable the compounds of formula (l) to be prepared in a neutral pH range of from about 6 to about 8. For example, in the preparation of the compounds of formula (l) from the compounds of formula (ll), this neutral pH range enables both the starting materials (compounds of formula (ll)), which are acid labile, and the final products (compounds of formula (l)), which are base labile, to be stable during the reaction. (6) The inventors have surprisingly found that, the use of a aining cation as Z+ (the proton source), conveniently s the ent preparation of compounds of formula (i) from compounds of formula (ii) in quantitative yield, and, as mentioned in point (5), in a neutral pH range. Without wishing to be bound by theory, it is proposed that Z, the proton source, must be a conjugated acid of an organic base which is protonated in an equilibrated manner within the neutral pH range. The inventors propose that, by using a aining cation as the proton source Z", the N atom of the proton source has a pKa greater than the pKa of the N atom of the dihydropyridine of the nd of a (ll). Therefore, in simple terms, due 40 to the relative pKa values, the N atom of the proton source Z+ (i.e. N-Hi) holds onto the proton H+ until after the N atom of the dihydropyridine has been oxidised (which oxidation, the inventors propose, is facilitated by the carbon—containing catalyst). It is only after the N atom of the dihydropyridine has been oxidised that it will be protonated by the proton source Z“. The inventors propose that if a proton source other than one containing a N atom is used, for example a phosphonium cation containing P-H+ or a sulfonium cation containing S- H, it is proposed that such proton sources would cause the pH of the reaction medium to fall below the neutral pH range, and the proton sources would release their protons in this lower pH range. it is proposed that this change would cause the N atom of the dihydropyridine to be protonated before oxidation, y resulting in the undesirable hydrolysis of a C-N bond of the dihydropyridine, it is also proposed that this resultant instability of the opyridine due to the undesirable ng of a C-N bond, would also occur using a weak acid (eg. carboxylic acid) or a strong acid (e.g. hydrochloric acid, phosphoric acid or sulphuric acid).

Thus, it is ed that only a N-containing cation as proposed, is capable of releasing a proton in a pH range (neutral) which allows the reaction to proceed as desired to form the compounds of formula (l) from the compounds of formula (ll).

Examples Embodiments of the present invention will now be described, with reference to the accompanying, non-limiting es and drawings, in which: Figure 1 shows the B-anomer forms of nicotinamide de, nicotinate riboside, namide mononucleotide and nicotinate mononucleotide, without counter ions; Figure 2 depicts Scheme A, which is a scheme illustrating, in l terms, that compounds of a (W) may be used to prepare compounds of formula (III), as described in Example 1; that compounds of formula (ll!) may be used to prepare compounds of formula (ll), as described in Example 2; and that compounds of formula (ll) may be used to prepare nds of formula (l), as described in Example 3; wherein n, m, Y, R1 — R3 and X' are as defined above; Figure 3 depicts Scheme B, which is a scheme illustrating, in general terms, that triacetyl namide riboside, trifiate salt may be used to prepare triacetyl~1,4—dihydronicotinamide de, as described in Example 1(A), and that triacetyl-1 ,4-dihydronicotinamide riboside may be used to prepare 1-(beta—D-ribofuranosyi)—1,4—dihydronicotinamide, as described in Example 2, and that 1- (beta-D-ribofuranosyl)—’l ,4-dihydronicotinamide may be used to prepare namide riboside, chloride salt, as described in Examples 3(A), 3(E) and 3(F). The B-anomers of all of the mentioned compounds are shown. It will be appreciated that Scheme B is merely exemplary and is not to be construed as limiting the invention o; 4o Figure 4 shows the B—anomer forms oftriacetyl-1,4—dihydronicotinamide riboside (Example 1(A)), tyl O-ethyl-1, dronicotinate riboside, (Example 1(8)), tribenzoyl—1,4—dihydronicotlnamide riboside le 1(0)), and 1—(beta-D—ribofuranosyl)—1,4-dihydronicotinamide (Example 2); and Figure 5 shows the B-anomer forms of nicotinamide riboside, chloride salt (Examples 3(A), 3(E) and 3(F)), nicotinamide riboside, acetate salt (Example 3(8)), nicotinamide riboside, formate salt (Example 3(C)), and nicotinamide riboside, trifluoroacetate salt (Example 3(D)).

Example 1 1O Compounds of formula (Ill) were prepared in accordance with the ion as follows. The pH of the on media described in the following examples was in the region of about 6—8.

Exam Ie 1 A : Pre aration of reduced triacet l nicotinamide riboside. namel triacet l-1.4- dihydronicotinamide riboside a compound of formula (ill) (the g-anomer form of which is shown in Figure 4).

Reduction: All solvents were degassed prior to use by sonication and argon ng. Sodium dithionite (0.6569, 3.76 mmol, 2 eq) and sodium hydrogencarbonate (0.799, 9.40 mmol, 5 eq) were added to a clean, dry round bottom ﬂask with a magnetic stirrer and placed under inert atmosphere.

A compound of formula (lW, namely triacetyl nicotinamide riboside, triﬂate (CF3803’, also known as —OTf) salt (19, 1.88 mmol, 1 eq) was then dissolved in a minimum amount of water (<10 ml) and slowly added to the reaction vessel. Once the reaction d, further water was added to the reaction until ail of the reactants had dissolved (<10 ml) and was left to stir for 20 minutes. The aqueous solution was then extracted with three half portions of dichloromethane (DCM). The DCM fractions were ted and concentrated under reduced pressure, ing the triacetyl~1, 4- dihydronlcotinamide riboside derivative (triacetyl-NRH) with residual amounts of starting material (<5%). The aqueous layer was subjected to the above conditions a second time to increase yields which ed 65%. Ethyl acetate was also an excellent alternative extraction solvent in place of DCM, yielding a 75% yield. lR (MeOD, 400MHz) — 57.15 (s, 1H, H-5), 5.95 (d, 1H, J: 7.21Hz, H—6), 5.25 (d, 1H, J=2.84Hz) & 5.17 (d, 1H, J=1.80Hz) (H-8 & H-7), 4.96 (d, 1H, J=7.09Hz, H~4), 4.87 (ABX, 1H, Jaa=8.18Hz, Jab=3.60Hz, H—9), 4.26 (d, 2H, J=3.20Hz, H—10 & H-10’) 4.19 (m, 1H, J=3.00Hz, H—3), 3.13 (m, 2H, J=1.18Hz, H—2), 2.13 (s, 3H), 2.11 (s, 3H), 2.10 (s, 3H) (H-13, H—15, H-17). 130—NMR (MeOD, 125MHz) — 5172.80 (0—11), 170.40 (C-12, C~14, 0—16), 137.90 (C-5), 125.20 (04), 105.12 (C-6), 95.24 (C-3), 83.49 (C—9), 71.18 (C~8), 70.26 (C—7), 61.55 (C-10), 22.16 (C—2), 21.52 (C-13, C-15, C» 17). HMRS m/z: 45; Calc. Mass: 383.1454.

The compound of formula (W), namely trlacetyl nicotinamide de, triflate (-OTf) salt was prepared as follows. Nicotinamide (10g, 81.89 mmol, 1eq) was silylated using TMSCl (15.6 ml, 40 122.85 mmol, 1.5 eq) in HMDS (100 ml) at 130°C in tative yield, in order to force the B- , selectivity via the following VorerQgen reaction. Ribose tetraacetate (also known as tetraacetate riboside) was reacted with the resultant silyiated nicotinamide in the presence of 5 equivalents of TMSOTf. The reactants were shaken in a 1.5 mi steel vessei with a 5 mm diameter steel bail bearing in a Retsch MM400 mixer mili at 25 Hz for 0.5 h. At this point the formed triacetylated nicotinamide riboside (compound of formula (iV)) could be isolated. it will be appreciated that the tyl nicotinamide riboside is not limited to being produced by this exact method, and could, for example, be produced using a conventional Vorbriiggen reaction as described, for example, in ational PCT patent publication no. or in T. Yang, N. Y. K. Chan and A. A. Sauve, Journal of Medicinal Chemistry, 2007, 50, 6458—6461. 1H—NMR (MeOD, 400MHz) — 5 9.61 (s, 1H, aromatic), 9.30 (dt, 1H, J=6.3, 1.4 Hz, aromatic), 9.10 (dt, 1H, J=8.2, 1.4 Hz, aromatic), 8.37 (dd, 1H, J=8.2, 6.3 Hz, aromatic), 6.60 (d, 1H, J=3.9 Hz, H—1 (anomeric)), 5.60 (dd, 1H, J=5.6, 3.9Hz, H-2), 5.46 (t, 1H, J=5.6 Hz, H-3), 4.81-4.84 (m, 1H, H-4), 4.61 (ABX, 1H, Ja,a:=13.1 Hz, Ja|b=3.5 Hz, H-5), 4.51 (ABX, 1H, Ja,a!=13.0 Hz, Ja,b=2.8 Hz, H-5'), 2.20 (s, 3H, OAc), 2.17 (s, 3H, OAc), 2.16 (s, 3H, OAc). 13C-NMR (MeOD, 125MHz) - 6 172.1, 171.6, 171.2 (3x Q=OCH3), 164.9 (Q=ONH2) 147.0, 144.3, 142.3, 136.2, 129.6, tic), 121.6 (q, J: 3202 Hz, CF3), 99.4 (C-1 (anomeric)), 84.4 (0—4), 77.6 (C-2), 70.7 (C-3), 63.5 (C—5), 20.7 (OAc), 20.3 (OAc), 20.2 (OAc). 1QF-NlVlR (MeOD, ) — 6 —79.9 (triﬂate counterion) e 1(B): ation of reduced mi nicotinate ester riboside, namely triacetyi O-ethyl-1, 4-dihydronicotinate riboside. a compound of formula (lll) (the g-anomer form of which is shown in Figure 4).

Reduction: A compound of formula (IV), namely triacetyi i nate riboside, triﬂate (—OTf) sait (2.309, 4.2mmol, 1eq) was dissolved in 20mL H20 and a solution of a solution of NaHCO3 (1.779, oi, Seq) and sodium dithionite (1.479, 8.22mmol, 2eq) in 30mL H20 was added and stirred for 2hrs. The yellow solution obtained was then washed with 2 x ethyl acetate (EtOAc, 40mL), the organic layer dried over M9804, ﬁltered and concentrated to provide 900mg (39% yield) of 2,3,5— triacetyi O-ethyl-i, 4- dihydronicotinate riboside (a yellow 05!) without further puriﬁcation. 80% purity based on 1H—NMR. 1H-NMR-o 7.27 (1H, s, H—6), 6.05 (1H, dd, J: 8.2, 1.5Hz, H-7), 5.26 (1H, dd, J: 5.8, 2.8Hz, H-3), .23 (1H, dd, J: 6.9, 5.8Hz, H-2), 5.08 (1H, d, J: 6.9Hz, H-1), 4.91 (1 H, dt, J: 8.3, 3.5Hz, H—8), 4.24- 4.30 (3H, m, H—4, H-5, H-5’), 4.11 (2H, 9, J: 7.2Hz, H—11), 3.04-3.06 (2H, m, H—9), 2.16 (3H, 5, OAc), 2.12 (3H, 5, OAc), 2.09 (3H, s, OAc), 1.25 (3H, t, J: 7.2Hz, H—12).

R— 6 172.2, 171.5, 171.3, 169.8, (3x Q=O-CH3 and Q=O-0Et), 139.9 (C—6), 126.3 (C-7), 106.4 (C—8), 101.5 (C-10), 94.2 (C—1), 80.4 (0-4), 72.3 (0—2), 72.1 (0-3), 64.8 (0—5), 61.0 (C-11), 23.4 (C- 9), 20.7, 20.5, 20.3 (3x C=O-_(;H3), 14.8 (0-12).

The compound of formula (W), namely tyi O~ethyl nicotinate riboside, triﬂate (—OTf) salt was 40 prepared as follows. Ribose tetraacetate (also known as tetraacetate riboside) was reacted with ethyl nicotinate (Sigma Aldrich) using the genera! bail milling Vorbrtiggen ure described in Exampie 2014/065971 1(A) above. The reactants, namely 1eq tetraacetate riboside, 1eq TMSOTf, 1eq ethyl nicotinate, were d for 30mins in a 1.5 ml steel vessel with a 1.5cm diameter steel ball bearing in a Retsch MM400 mixer mill at 25 Hz. The crude reaction mixture ining some unreacted ethyl nicotinate and starting sugar, <10%) was used for the reduction step (described above) without further puriﬁcation. It will be appreciated that the triacetyl O—ethyl nicotinate riboside, triflate (-OTf) salt is not limited to being produced by this exact method, and could, for example, be produced using a conventional ‘iggen reaction as described for example, in international PCT patent publication no. or in T. Yang, N. Y. K. Chan and A. A. Sauve, Journal of Medicinal Chemistry, 2007, 50, 6458—6461. 1O lR (D20, 400MHz) — 5 9.45 (s, 1H, aromatic), 9.14 (d, 1H, J=6.1 Hz, aromatic), 9.02 (d, 1H, J=7.8 Hz, aromatic), 8.18 (t, 1H, J=6.7 Hz, aromatic), 6.51 (d, 1H, J=4.1 Hz, H-1 (anomeric)), 5.47 (t, 1H, J=4.4 Hz, H-2), 5.36 (t, 1H, J=4.7 Hz, H-3), 4.81-4.84 (m, 1H, H-4), 4.45—4.48 (m, 2H, H~5), 4.36 (q, 2H, J=7.0 Hz, C=OCﬁ2CH3), 2.04 (s, 3H, OAc), 2.02 (s, 3H, OAc), 1.98 (s, 3H, OAc), 1.25 (t, 3H, J=7.0 Hz, CH3). ‘gF-NMR (ozo, 376MHz) — 6 -790 (triflate counterion) Example 1(C): Preparation of reduced tribenzoyl nicotinamide riboside, namely tribenzoyl—1, 4- dihydronicotinamide riboside, a compound of formula (ill) (the ﬁ-anomer form of which is shown in Figure 4). ion imised): A compound of formula (IV), namely tribenzoyl nicotinamide riboside, triflate (—OTf) salt was dissolved in minimal methanol and transferred to a round bottomed flask, 10mL of H20 was added to the on and most of the methanol removed via rotary evaporation.

The starting al crashed out of solution and 20mL of diethyl ether (EtZO) was added until the solids solubilized into a biphasic system. A solution of NaHC03 (420mg, 5mmol, Seq) and sodium dithionite (348mg, 2mmol, 2eq) in 10mL H20 was added and stirred for 2hrs. The layers were separated and the ether layer was dried over MgSO4 and concentrated to provide 428mg (76% yield) of zoyl-1, 4-dihydronicotinamide riboside (yellow solid) t further puriﬁcation. 80% purity based on 1H-NMR. Pure material is obtained by Biotage puriﬁcation. 3O 1H-NMR- 5 8.01-8.04 (2H, m, 0B2), 7.81—7.86 (4H, m, 082), 7.25-7.55 (9H, m, 082), 7.13 (1H, s, H— 6), 6.01 (1H, dd, J: 8.2, 1.5Hz, H-7), 5.68 (1H, dd, J: 6.2, 3.5Hz, H—3), 5.57 (1H, dd, J: 6.7, 6.2Hz, H-2), 5.29 (1H, cl, J: 6.7Hz, H-1), 4.61-4.68 (2H, m, H—8, H—5), 4.50-4.55 (2H, m, H-4, H-5’), 3.93— 3.94 (2H, m, H-9). 13C-NMR- 6 172.7, 167.6, 166.7, 166.6 (3x CGH5, Q=ONH2), 138.1 ((3-6), 134.9, 134.8, 134.6, 130.9, 130.8, 130.7, 130.3, 130.0, 129.8, 129.7 (3x 032), 125.7 (C-7), 105.9 ((3-8), 94.9 (0-1), 80.3 (C—4), 72.9 (0-2), 72.7 (C-3), 65.4 (C-5), 23.6 ((3-9).

The compound of formula (W), namely tribenzoyl nicotinamide riboside, triflate (-OTf) salt was prepared as follows. Ribose tetraacetate (also known as tetraacetate riboside) was reacted with 40 TMS—nicotinamide (trimethylsilyl N-trimethylsilylpyridine-B-Carboximidate, available from Sigma- h) using the l ball milling VorbriJggen procedure described in Example 1(A) above. The WO 14722 reactants, namely 1eq 1-acetate-tribenzoate riboside, 1eq TMSOTf and 1eq TMS—nicotinamide, were reacted for 30mins in a 1.5 ml steel vessel with a 1.5cm diameter steel ball bearing in a Retsch MM4OO mixer mill at 25 Hz. 1eq of DCE (dichloroethylene) was required and the crude reaction mixture (containing some unreacted nicotinamide and starting benzoate sugar, <10%) was used for the reduction step (described above) without further puriﬁcation. It will be appreciated that the tribenzoyl nicotinamide riboside, triflate (—OTf) salt is not limited to being produced by this exact , and could, for example, be produced using a conventional Vorbrtrggen reaction as described, for example, in international PCT patent publication no. or in T. Yang, N. Y. K. Chan and A. A. Sauve, Journal of Medicinal try, 2007, 50, 6458—6461. 1O 1H—NMR (MeOD, ) — 6 9.59 (s, 1H, aromatic), 9.31 (cl, 1H, J=6.4 Hz, ic), 8.94 (d, 1H, J=8.1 Hz, aromatic), 8.15 (dd, 1H, J=8.1, 6.4 Hz, aromatic), 7.90-7.94 (m, 6H, OBz), 7.50-7.54 (m, SH, 082), .38 (m, 6H, 08.2), 6.79 (d, 1H, J=3.9 Hz, H-1 (anomeric)), 5.97 (dd, 1H, J=5,6, 3.9Hz, H~2), 5.87 (t, 1H, J=5.6 Hz, H—3), 5.13-5.16 (m, 1H, H-4), 4.83—4.91 (m, 2H, H—5). 19F-NMR (MeOD, 376MHz) ~ 5 -791 (triﬂate counterion) A compound of formula (ll), nameiy NRH ed nicotinamide riboside, also known as 1-(beta—D- ribofuranosyl)-1,4—dihydronicotinamide (the B-anomer form of which is shown in Figure 4) was prepared as follows. The pH of the reaction medium described in the following example was in the region of about 6—8. d triacetyl nicotinamide riboside, namely triacetyl—1, 4—dihydronicotinamide riboside, a compound of formula (Ill), prepared in Example 1(A) above, was deprotected using mechanochemical (MeOH, NaOH) processes to remove the acetyl moiety afforded NRH quantitatively. 100mgs of (ill) was dissolved in 0.5mL of MeOH containing 0.05g of NaOH. The nds were reacted for 30mins in a 1.5 ml steel vessel with a 1.5cm diameter steel ball bearing in a Retsch MM400 mixer mill at 25 Hz. 1H—NMR (MeOD, 400MHz) — 57.18 (s, 1H, H-5), 6.14 (d, 1H, J: 8.28Hz, H-6), 4.85 (m, 1H, H-3), 4.76 (d, 1H, J: 5.77Hz, H-4), 4.04 (m, 2H, H~7&H-8), 3.93 (m, 1H, J=2.76, H-9), 3.72 (ABX, 1H, Jaa=12.55Hz, Jab=3.51Hz, H—10), 3.65 (ABX, 1H, Jaa=12.55Hz, Jab=4.02Hz, H—10’), 3.10 (q, 2H, Hz H-2). 13C—NMR (MeOD, 125MHz) — 6172.88 ((3-11), 137.83 (0-5), 125.29 (0-4), 105.19 (C—B), 95.00 (C-3), 83.54 (C-9), 71.10 ((3-8), 70.20 (C-7), 61.61 (0—10), 22.09 (C-2); HRMS m/z: 257.1130; Calc. Mass: 257.1137. it will be appreciated that the deprotection step as described above may be used to deprotect any other compound of formula (lll), including, but not limited to, reduced triacetyl nicotinate ester riboside, namely 2,3,5-triacetyl l-1, 4—dihydronicotinate riboside, ed in Example 1(8), and reduced tribenzoyl nicotinamide riboside, namely tribenzoyl-1, dronicotinamide riboside, 40 prepared in Example 1(0). The deprotection step may also be modiﬁed to suit particular requirements.

Example 3 Compounds of formula (I) were prepared in accordance with the ion as follows. The pH of the reaction media described in the following es was in the region of about 6-8.

Exam le 3 A : Pre aration of nicotinamide de chloride salt the —anomer form of which is 1O shown in Figure 5).

A compound of formula (ll), namely NRH (reduced nicotinamide riboside, shown in Figure 2; 50mg, 0.20mmol, 1eq), was dissolved in 5mL H20 and then 1eq (i.e. 0.20mmol) of ammonium chloride was added in one portion. Activated charcoal , i.e. 0.80mmol) was then added and the mixture stirred at RT for ~1hr and then ﬁltered and freeze—dried to give the chloride salt of nicotinamide riboside, quantitatively, i.e. 100% conversion and pure product. 1H-NMR (D20, ) ~ 6 9.46 (s, 1H, aromatic), 9.12 (dt, 1H, J=6.3, 1.4 Hz, aromatic), 8.83 (dt, 1H, J=8.2, 1.4 Hz, aromatic), 8.13 (dd, 1H, J=8.2, 6.3 Hz, aromatic), 6.13 (d, 1H, J=4.3 Hz, H—1 (anomeric)), 4.37 (t, 1H, J=4.7Hz, H-2), 4.31-4.34 (m, 1H, H-4), 4.21 (t, 1H, J=4.7Hz, H—3), 3.90 (ABX, ‘lH, Ja,a-=13.0 Hz, Ja,b=3.5 Hz, H—5), 3.75 (ABX, 1H, JaIa-=13.O Hz, Ja'_b=2.8 Hz, H-5’). lt will be appreciated that the NRH may be that ed in Example 2, or may be obtained commercially from eg. Diverchim, 100, rue Louis Blane, 60 765 Montataire Cedex, France — (CAS Registry Number:19132—12~8) either as a pure product or as a mixture of anomers.

Exam le 3 B : Pre aration of nicotinamide riboside acetate salt the —anomer form of which is shown in Figure 5).

The method described in Example 3(A) was carried out, except that 1eq (i.e. 0.20mmol) of ammonium acetate was added. The acetate salt of nicotinamide riboside was obtained, quantitatively. 1H—NMR (D20, ) ~ 6 9.46 (s, 1H, aromatic), 9.12 (d, 1H, J=6.3 Hz, aromatic), 8.83 (d, 1H, J=8.2 Hz, aromatic), 8.12 (m, 1H, ic), 6.09 (d, 1H, J=4.4 Hz, H—1 (anomeric)), 4.36 (t, 1H, J=4.7Hz, H-2), 4.32-4.35 (m, 1H, H—4), 4.21 (t, 1H, J:4.7Hz, H-3), 3.91 (ABX, 1H, 13.1 Hz, Ja,b=2.8 Hz, H—5), 3.75 (ABX, 1H, Javay=13.0 Hz, 3.5 Hz, H-5'), 1.79 (s, 3H, OAc).

Exam le 3 C : Pre aration of nicotinamide riboside formate salt the -anomer form of which is shown in Figure 5).

The method described in Example 3(A) was carried out, except that 1eq (i.e. 0.20mmol) of ammonium formate (methanoate) was added. The formate salt of nicotinamide riboside was obtained, quantitatively. 1H-NMR (D20, 400MHz) - 6 9.46 (s, 1H, aromatic), 9.12 (d, 1H, J=6.3 Hz, aromatic), 8.83 (d, 1H, J=8.2 Hz, aromatic), 8.29 (s, 1H, formate), 8.12 (m, 1H, aromatic), 6.09 (d, 1H, J=4.4 Hz, H~1 (anomeric)), 4.36 (t, 1H, J=4.7Hz, H-2), 4.31-4.34 (m, 1H, H—4), 4.21 (t, 1H, J=4.7Hz, H—3). 3.91 (ABX, 1H, 13-1 Hz, Ja,b=3.5 Hz, H-5), 3.79 (ABX, 1H, Ja‘a:=13.0 Hz, 2.8 Hz, H-5').

Exam le 3 D : Pre aration of nicotinamide riboside oroacetate salt the -anomer form of which 1O is shown in Figure 5).

The method described in Example 3(A) was carried out, except that 1eq (i.e. ol) of ammonium triﬂuoroacetate was added. The trifluoroacetate salt of nicontinamide riboside was obtained, quantitatively. 1H-NMR (D20, ) - 6 9.46 (s, 1H, aromatic), 9.12 (d, 1H, J=6.3Hz, aromatic), 8.83 (d, 1H, J=8.2, aromatic), 8.13 (dd, 1H, J=8.2. 6.3 Hz, aromatic), 6.13 (d, 1H, J=4.3 Hz, H-1 (anomeric)), 4.35 (t, 1H, J=4.7Hz, H-2), 4.31-4.34 (m, 1H, H—4), 4.20 (t, 1H, J=4.7Hz, H-3), 3.89 (ABX, 1H, Jalai=130 Hz, Ja'b=3.6 Hz, H-5), 3.74 (ABX, 1H, Ja,a.=13.o Hz, Jagb=2.9 Hz, H-5'). 19F-NMR (ozo, 376MHz)— 5 - 75.7 COO').

Exam le 3 E : Pre aration of nicotinamide riboside chloride salt the -anomer form of which is shown in Figure 5).

An alternative method to that described in Example 3(A) was carried out as s. NRH (reduced nicotinamide riboside, shown in Figure 4; 50mg, 0.20mmol, teq) was dissolved in 5mL H20:EtOAc (1:1) and then 1eq. (i.e. 0.20mmol) of ammonium de was added in one portion. Upon work-up after 1 hr, no oxidation had taken place and the starting materials were fully recovered. The recovered NRH and ammonium chloride were re—suspended in the same solvent system with addition of activated charcoal (~10mg. i.e. l) and stirred at RT for 1 hr. Subsequent ﬁltration 3O and freeze-drying afforded the chloride salt of nicotinamide riboside in quantitative yield. Thus it was ded that a carbon-containing catalyst, e.g. activated al, was essential to the method. 1H—NMR (020, 400MHz) — 6 9.46 (s, 1H, aromatic), 9.12 (dt, 1H, J=6.3, 1.4 Hz, aromatic), 8.83 (dt, 1H, J=8.2, 1.4 Hz, aromatic), 8.13 (dd, 1H, J=8.2, 6.3 Hz, aromatic), 6.13 (d, 1H, J=4.3 Hz, H—1 (anomeric)), 4.37 (t, 1H, J=4.7Hz, H-2), 4.31—4.34 (m, 1H, H—4), 4.21 (t, 1H, J=4.7Hz, H~3), 3.90 (ABX, 1H, Ja,a’=13.0 Hz, Ja,b=3.5 Hz, H—5), 3.75 (ABX, 1H, Ja,a'=13.0 Hz, Ja',b=2.8 Hz, H—5‘).

Exam le 3 F : Pre aration of namide riboside chloride salt the -anomer form of which is shown in Figure 5). 4O The method described in e 3(E) was carried out, except that NRH (reduced nicotinamide riboside, shown in Figure 4; 50mg, 0.20mmol, 1eq) was dissolved in 5mL H20:THF (1:1), instead of H201EtOAc (1:1), and then 1eq (i.e. 0.20mmol) of ammonium chloride was added in one portion. Upon work-up after 1 hr, no ion had taken place and the starting materials were fully red. The recovered NRH and ammonium chloride were resuspended in the same solvent system with addition of ted charcoal (~10mg, i.e. 0.8mmol) and stirred at RT for 1 hr. uent ﬁltration and freeze-drying afforded the chloride salt of nicotinamide riboside in quantitative yield. Thus it was concluded that a carbon-containing catalyst, e.g. activated charcoal, was essential to the method. 1H—NMR (D20, 400MHz) — 6 9.46 (s, 1H, aromatic), 9.12 (dt, 1H, J=6.3, 1.4 Hz, aromatic), 8.83 (dt, 1H, J=8.2, 1.4 Hz, aromatic), 8.13 (dd, 1H, J=8.2, 6.3 Hz, aromatic), 6.13 (d, 1H, J=4.3 Hz, H-1 (anomeric)), 4.37 (t, 1H, J=4.7Hz, H—2), 4.31-4.34 (m, 1H, H—4), 4.21 (t, 1H, J=4.7Hz, H-3), 3.90 (ABX, 1H, Ja‘a>=13.0 Hz, Ja,b=3.5 Hz, H-5), 3.75 (ABX, 1H, Ja,ai=13.0 Hz, Jajb=2.8 Hz, H—5').

Claims

1. A method of preparing a compound of formula (I) wherein 10 n is 0 or 1; m is 0 or 1; Y is O or S; R1 is selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, tuted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted primary or secondary amino, and substituted or unsubstituted azido; 20 R2 – R5, which may be the same or different, are each independently ed from H, substituted or unsubstituted alkyl, tuted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, and tuted or unsubstituted aryl; and X- is an anion, selected from an anion of a substituted or tituted carboxylic acid, a halide, a 25 substituted or unsubstituted sulfonate, a substituted or unsubstituted phosphate, a substituted or unsubstituted sulfate, a substituted or unsubstituted carbonate, and a substituted or unsubstituted carbamate; comprising reacting a compound of formula (II) (II) 5 wherein n, m, Y and R1 – R5 are as defined above; with a compound of the formula Z+X-, wherein X- is as defined above, and wherein Z+ is a N-containing cation; in the ce of an aqueous solution and a carbon-containing catalyst, wherein the carboncontaining catalyst is activated charcoal; to form the compound of formula (I).

2. A method according to claim 1, wherein Z+ is selected from a substituted or unsubstituted ammonium, a tuted or unsubstituted pyridinium, a substituted or unsubstituted idinium, a 20 substituted or unsubstituted imidazolium and a substituted or unsubstituted triazolium.

3. A method according to claim 1 or claim 2, wherein Z+ is a substituted or unsubstituted ammonium of the formula ˡˡRˡˡˡ, wherein Rˡ, Rˡˡ and Rˡˡˡ, which may be the same or different, are each independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted 25 alkenyl, tuted or unsubstituted alkynyl, and substituted or unsubstituted aryl.

4. A method according to any one of claims 1 to 3, wherein Z+ is an unsubstituted ammonium of the formula NH4+. 30

5. A method according to any ing claim, wherein the aqueous solution comprises, in addition to water, an organic solvent.

6. A method according to claim 5, wherein the aqueous solution ses water and organic solvent in a respective ratio by volume of from 1:5 to 5:1, optionally from 1:3 to 3:1, r optionally from 1:2 to 2:1, still further optionally 1:1. 5

7. A method according to claim 5 or claim 6, wherein the organic solvent is selected from a substituted or unsubstituted ether, a substituted or unsubstituted ester, a substituted or unsubstituted ketone, a substituted or unsubstituted aliphatic or aromatic hydrocarbon, or a combination thereof.

8. A method according to any one of claims 5 to 7, wherein the organic solvent comprises an 10 ether selected from diethyl ether, methyl tert-butyl ether, ethyl utyl ether, di-tert-butyl ether, diisopropyl ether, dimethoxymethane, tetrahydrofuran, 2-methyltetrahydrofuran, and tetrahydropyran, or a combination thereof.

9. A method according to any one of claims 5 to 8, wherein the organic t comprises an ester selected from methyl acetate, ethyl acetate, isopropyl e, n-propyl acetate, isobutyl 15 acetate and n-butyl acetate, or a ation thereof.

10. A method according to any one of claims 5 to 9, wherein the organic solvent comprises a ketone selected from methyl isobutyl ketone and methyl isopropyl ketone, or a ation thereof.

11. A method ing to any one of claims 5 to 10, wherein the organic t comprises an 20 unsubstituted aliphatic arbon solvent ed from pentane, hexane, cyclohexane and heptane, or a ation thereof.

12. A method according to any one of claims 5 to 11, wherein the organic solvent comprises a substituted aliphatic hydrocarbon solvent, optionally a halogenated aliphatic hydrocarbon solvent, 25 further optionally a chlorinated aliphatic hydrocarbon solvent selected from romethane, trichloromethane, tetrachloromethane, 1,2-chloroethane, 1, 1, 1-trichloroethane and trichloroethylene, or a combination thereof.

13. A method according to any one of claims 5 to 12, wherein the organic solvent comprises an 30 aromatic hydrocarbon solvent selected from benzene, toluene, ethylbenzene and xylene, or a combination f.

14. A method according to any preceding claim, wherein the compound of formula (II) and the compound of the formula Z+X- are present in a respective molar ratio of from 1:5 to 5:1, optionally 35 from 1:3 to 3:1, further optionally from 1:2 to 2:1, still further optionally 1:1.

15. A method according to any preceding claim, wherein the compound of formula (II) and the carbon-containing catalyst are t in a respective molar ratio of from 10:1 to 1:10, ally from 5:1 to 1:5, further optionally from 4:1 to 1:4, still further optionally 1:1 or 1:2 or 1:3 or 1:4.

16. A method ing to any ing claim, wherein the reaction is carried out in a pH range of from 6 to 8, optionally from 6.5 to 7.5.

17. A method according to any preceding claim, wherein the on is carried out at a 5 temperature of from 10°C to 40°C, optionally from 15°C to 35°C, further optionally from 15°C to 30°C, still further optionally from 15°C to 20°C, even further optionally from 20°C to 25°C, even r optionally at a temperature of 20°C or 21°C or 22°C or 23°C or 24°C or 25°C.

18. A method according to any preceding claim, wherein the on is d out for a period 10 of time of from 1 minute to 180 minutes, optionally from 2 minutes to 120 minutes, further optionally from 5 s to 120 minutes, still further optionally from 10 s to 120 minutes, even further ally from 20 minutes to 120 minutes, even further optionally from 30 minutes to 120 minutes, still further optionally from 60 minutes to 120 minutes, even further optionally from 60 minutes to 90 minutes, still r ally 60 minutes or 70 minutes or 80 minutes.

19. A method according to any preceding claim, wherein X- is an anion of a substituted or unsubstituted carboxylic acid selected from an anion of a substituted or unsubstituted monocarboxylic acid and an anion of a substituted or unsubstituted dicarboxylic acid.

20 20. A method according to claim 19, wherein X- is an anion of a substituted monocarboxylic acid, optionally an anion of a substituted propanoic acid or an anion of a substituted acetic acid.

21. A method according to claim 20, wherein X- is an anion of a substituted propanoic acid, optionally an anion of a hydroxy propanoic acid, further optionally an anion of 2-hydroxypropanoic 25 acid, being e.

22. A method according to claim 20, n X- is an anion of a substituted acetic acid, being a substituted acetate, optionally a trihaloacetate selected from trichloroacetate, tribromoacetate and trifluoroacetate, further optionally trifluoroacetate.

23. A method according to claim 19, wherein X- is an anion of an unsubstituted rboxylic acid selected from formic acid, acetic acid, propionic acid and butyric acid, being formate, acetate, propionate and butyrate, respectively. 35

24. A method according to claim 19, wherein X- is an anion of a substituted or unsubstituted amino-monocarboxylic acid or an anion of a substituted or unsubstituted amino-dicarboxylic acid, wherein, optionally, X- is an anion of an amino-dicarboxylic acid, further optionally selected from glutamic acid and aspartic acid, being glutamate and aspartate, respectively. 40

25. A method according to claim 19, wherein X- is an anion of ascorbic acid, being ascorbate.

26. A method according to any one of claims 1 to 18, n X- is a halide ed from chloride, bromide, fluoride and iodide, optionally chloride or bromide. 5

27. A method according to any one of claims 1 to 18, wherein X- is selected from chloride, acetate, formate, trifluoroacetate, ascorbate, aspartate, glutamate and lactate, optionally selected from chloride, acetate, formate and trifluoroacetate.

28. A method according to any one of claims 1 to 18, wherein the compound of the formula Z+X- 10 is selected from ammonium chloride, ammonium acetate, ammonium e, ammonium trifluoroacetate, ammonium ascorbate, um aspartate, ammonium ate and ammonium lactate, optionally selected from ammonium chloride, ammonium acetate, ammonium formate and ammonium trifluoroacetate. 15

29. A method according to any preceding claim, wherein the method further comprises a tion step to remove the carbon-containing stfrom the compound of formula (I).

30. A method according to any one of claims 1 to 18, wherein, in the compound of formula (I), n is 0, m is 1, R1 is NH2, R2 – R5 are each H, and X- is selected from chloride, acetate, formate and 20 trifluoroacetate.

31. A method according to any preceding claim, wherein the compound of a (II) is prepared by reacting a nd of formula (III) (III) wherein 30 n, m, Y and R1 – R5 are as defined in the preceding claims; and R6, R7 and R8, which may be the same or different, are each independently a hydroxyl-protecting group; with a deprotecting agent; to form the compound of formula (II).

32. A method according to claim 31, n R6, R7 and R8 are each independently an ester-type protecting group, an ether-type ting group, or a silyl-type protecting group.

33. A method according to claim 32, wherein an ester-type ting group is a protecting group 10 ed from acetyl, propionyl, isopropionyl, benzoyl, and trihaloacetyl, optionally trifluoroacetyl or trichloroacetyl.

34. A method according to claim 32, n an ether-type protecting group is a protecting group selected from benzyl, p-methoxybenzyl, methoxymethyl and allyl ethers.

35. A method according to claim 32, wherein a silyl-type protecting group is a protecting group selected from trimethylsilyl, ylsilyl, triisopropylsilyl, 2-(trimethylsilyl)ethoxymethyl, tertbutyldimethylsilyl , tert-butyldiphenylsilyl and tetraisopropyldisilyl. 20

36. A method according to any one of claims 31 to 33, wherein the R6, R7 and R8 moieties are selected from tuted and unsubstituted acetyl, and substituted and unsubstituted benzoyl.

37. A method according to claim 36, wherein least two of R6, R7 and R8 are ed from unsubstituted acetyl or unsubstituted benzoyl.

38. A method according to any one of claims 31 to 37, wherein the deprotecting agent is an acid or a base.

39. A method according to claim 37, wherein R6, R7 and R8 each comprise unsubstituted acetyl 30 or unsubstituted benzoyl and the deprotecting agent is a base, ally selected from NH3, Na2CO3 and NaOH.

40. A method according to any one of claims 31 to 39, wherein the reaction is carried out in the presence of a protic or aprotic solvent or a combination thereof.

41. A method according to claim 41, wherein the reaction is carried out in the presence of a protic solvent selected from water, substituted or unsubstituted alcohol, or a combination thereof.

42. A method according to claim 42, wherein the reaction is d out in the presence of 40 methanol.

43. A method according to any one of claims 31 to 42, wherein the reactants are subjected to mechanical ng, optionally using a ball milling or planetary ball milling machine.

44. A method according to any one of claims 31 to 43, wherein, in the compound of formula (III), 5 n is 0, m is 1, R1 is NH2, R2 – R5 are each H, and R6 – R8 are each acetyl.

45. A method according to any one of claims 31 to 43, wherein, in the compound of formula (III), n is 1, Y is O, m is 1, R1 is ethyl, R2 – R5 are each H, and R6 – R8 are each acetyl. 10

46. A method according to any one of claims 31 to 43, wherein, in the compound of formula (III), n is 0, m is 1, R1 is NH2, R2 – R5 are each H, and R6 – R8 are each benzoyl.

47. A method according to any one of claims 31 to 46, wherein the nd of formula (III) is prepared by reacting a nd of formula (IV) (IV) wherein n, m, Y, R1 – R8 and X- are as defined in the preceding claims; with a reducing agent, 25 an aqueous solution, and an organic solvent, to form a compound of a (III).

48. A method according to claim 47, n the organic solvent is as defined in any one of claims 7 to 13.

49. A method according to claim 47 or claim 48, wherein when at least two of R6, R7 and R8 comprise unsubstituted acetyl, the organic solvent is selected from dichloromethane, 1,2- chloroethane, n-butyl acetate, chloroform and ethyl e, or a combination thereof, r optionally ethyl acetate.

50. A method according to claim 47 or claim 48, n when at least two of R2, R3 and R4 comprise unsubstituted l, the organic solvent is selected from trichloroethylene, carbon tetrachloride, diisopropyl ether, toluene, methyl tert-butyl ether, benzene and diethyl ether, or a ation thereof, further optionally diethyl ether.

51. A method according to any one of claims 47 to 50, wherein the reducing agent is selected from sodium dithionite or sodium borohydride.

52. A method according to any one of claims 47 to 51, wherein the method comprises the 15 additional steps of separating the c phase from the aqueous phase; and extracting the compound of formula (III) from the organic solvent.

53. A method according to any one of claims 47 to 52, wherein the reactants are subjected to 20 mechanical grinding, optionally using a ball mill or planetary ball milling machine.

54. A method according to any one of claims 47 to 53, wherein, in the compound of formula (IV), n is 0, m is 1, R1 is NH2, R2 – R5 are each H, R6 – R8 are each acetyl, and X- is -OTf. 25

55. A method according to any one of claims 47 to 53, wherein, in the compound of formula (IV), n is 1, Y is O, m is 1, R1 is ethyl, R2 – R5 are each H, R6 – R8 are each acetyl, and X- is -OTf.

56. A method ing to any one of claims 47 to 53, wherein, in the compound of formula (IV), n is 0, m is 1, R1 is NH2, R2 – R5 are each H, and R6 – R8 are each benzoyl, and X- is -OTf. 30

57. A method according to any one of claims 1 to 56, wherein the activated charcoal acts as a support for a metal, the metal optionally including tion metals.

58. A method according to claim 57, wherein the metal includes tion metals. WO 14722 HowN+ / NH2 \o ,, O \\ ’4 Nicotinamide riboside HowN+ / OH @‘° ”2 O HO 6/ Nicotinate riboside N+ / NH2 \P/O / c , N / OH \P/O 0 HO Nicotinate mononucleotide