58-08-2

Multiplexed detection and quantification of structurally similar drug molecules, methylxanthine MeX, incl. theobromine TBR, theophylline TPH and caffeine CAF, have been demonstratedviasolution-based surface-enhanced Raman spectroscopy (SERS), achieving highly reproducible SERS signals with detection limits down to ～50 nM for TBR and TPH, and ～1 μM for CAF. Our SERS substrates are formed by aqueous self-assembly of gold nanoparticles (Au NPs) and supramolecular host molecules, cucurbit[n]urils (CBn,n= 7, 8). We demonstrate that the binding constants can be significantly increased using a host-guest size matching approach, which enables effective enrichment of analyte molecules in close proximity to the plasmonic hotspots. The dynamic range and the robustness of the sensing scheme can be extended using machine learning algorithms, which shows promise for potential applications in therapeutic drug monitoring, food processing, forensics and veterinary science.

In this paper, a green process for the synthesis and separation of caffeine was reported. Theophylline sodium is used as the raw material, diazabicyclo[5.4.0]undec-7-ene as the catalyst, and Turkey red oil as the solvent, particularly, dimethyl carbonate was adopted in place of high toxic dimethyl sulfate to form a mixture of caffeine and by-product sodium bicarbonate. After converting sodium bicarbonate to sodium carbonate, the solubility difference between caffeine and sodium carbonate at 40°C was for the first time utilized to achieve the purpose of separating caffeine with an excellent yield of 98.4% and a purity of greater than 99.0%. Furthermore, both the reaction mother liquor and separation mother liquor can be recycled and reused during the reaction and separation processes, respectively, with little caffeine loss. No industrial waste was discharged in the process of the improved synthesis and separation, which is therefore environmental friendly.

The invention discloses a method for synthesizing caffeine, and relates to the technical field of preparation of heterocyclic compounds containing purine ring systems. The preparation method comprisesthe following steps: mixing cyanoacetic acid and acetic anhydride at 30-80 DEG C for reaction, adding a solvent and dimethylurea, cooling to room temperature after reflux reaction is finished, filtering, concentrating filtrate, combining solids to obtain dimethylacetamide, adding liquid caustic soda to adjust the pH to 8-11, and reacting at 80-100 DEG C to generate dimethyl 4AU; the method comprises the following steps: completely dissolving dimethyl 4AU in formic acid, adding sodium nitrite, reacting at room temperature, adding a catalyst, keeping the temperature at 30-70 DEG C, recovering the catalyst after the reaction is finished, and concentrating mother liquor to recover formic acid, thereby obtaining dimethyl FAU; adding water and liquid caustic soda into dimethyl FAU, and carryingout a ring-closure reaction to obtain theophylline sodium salt; the theophylline sodium salt is subjected to methylation reaction and refining to obtain caffeine. The method has the advantages of accessible raw materials, mild and controllable reaction conditions, fewer steps, high yield and greatly higher product quality, is simple to operate, and can easily implement industrial production.

Dehydroxymethylation, the direct conversion of alcohol feedstocks as alkyl synthons containing one less carbon atom, is an unconventional and underexplored strategy to exploit the ubiquity and robustness of alcohol materials. Under mild and redox-neutral reaction conditions, utilizing inexpensive cerium catalyst, the photocatalytic dehydroxymethylation platform has been furnished. Enabled by ligand-to-metal charge transfer catalysis, an alcohol functionality has been reliably transferred into nucleophilic radicals with the loss of one molecule of formaldehyde. Intriguingly, we found that the dehydroxymethylation process can be significantly promoted by the cerium catalyst, and the stabilization effect of the fragmented radicals also plays a significant role. This operationally simple protocol has enabled the direct utilization of primary alcohols as unconventional alkyl nucleophiles for radical-mediated 1,4-conjugate additions with Michael acceptors. A broad range of alcohols, from simple ethanol to complex nucleosides and steroids, have been successfully applied to this fragment coupling transformation. Furthermore, the modularity of this catalytic system has been demonstrated in diversified radical-mediated transformations including hydrogenation, amination, alkenylation, and oxidation.

Dehydroxymethylation, the direct conversion of alcohol feedstocks as alkyl synthons containing one less carbon atom, is an unconventional and underexplored strategy to exploit the ubiquity and robustness of alcohol materials. Under mild and redox-neutral reaction conditions, utilizing inexpensive cerium catalyst, the photocatalytic dehydroxymethylation platform has been furnished. Enabled by ligand-to-metal charge transfer catalysis, an alcohol functionality has been reliably transferred into nucleophilic radicals with the loss of one molecule of formaldehyde. Intriguingly, we found that the dehydroxymethylation process can be significantly promoted by the cerium catalyst, and the stabilization effect of the fragmented radicals also plays a significant role. This operationally simple protocol has enabled the direct utilization of primary alcohols as unconventional alkyl nucleophiles for radical-mediated 1,4-conjugate additions with Michael acceptors. A broad range of alcohols, from simple ethanol to complex nucleosides and steroids, have been successfully applied to this fragment coupling transformation. Furthermore, the modularity of this catalytic system has been demonstrated in diversified radical-mediated transformations including hydrogenation, amination, alkenylation, and oxidation.

Pd-catalyzed direct C2-alkenylation of azole derivatives proceeds efficiently under mild conditions, and the reaction of substituted benzoxazoles, oxazole and benzothiazole occurred even at room temperature. The substrate scope of the reaction was turned out to include mono-, di- and trisubstituted alkenyl bromides. To validate the scalability of this method, 5-Methyl-2-(prop-1-en-2-yl)benzoxazole (3c) was prepared on one-gram scale at room temperature.

Over the past three decades, considerable progress has been made in the development of methods to construct sp 2 carbon-nitrogen (C-N) bonds using palladium, copper or nickel catalysis 1,2 . However, the incorporation of alkyl substrates to form sp 3 C-N bonds remains one of the major challenges in the field of cross-coupling chemistry. Here we demonstrate that the synergistic combination of copper catalysis and photoredox catalysis can provide a general platform from which to address this challenge. This cross-coupling system uses naturally abundant alkyl carboxylic acids and commercially available nitrogen nucleophiles as coupling partners. It is applicable to a wide variety of primary, secondary and tertiary alkyl carboxylic acids (through iodonium activation), as well as a vast array of nitrogen nucleophiles: nitrogen heterocycles, amides, sulfonamides and anilines can undergo C-N coupling to provide N-alkyl products in good to excellent efficiency, at room temperature and on short timescales (five minutes to one hour). We demonstrate that this C-N coupling protocol proceeds with high regioselectivity using substrates that contain several amine groups, and can also be applied to complex drug molecules, enabling the rapid construction of molecular complexity and the late-stage functionalization of bioactive pharmaceuticals.

Caffeine-oxalic acid cocrystal, widely reported to be stable under high humidity, dissociated in the presence of numerous pharmaceutical excipients. In cocrystal-excipient binary systems, the water mediated dissociation reaction occurred under pharmaceutically relevant storage conditions. Powder X-ray diffractometry was used to identify the dissociated products obtained as a consequence of coformer-excipient interaction. The proposed cocrystal dissociation mechanism involved water sorption, dissolution of cocrystal and excipient in the sorbed water, proton transfer from oxalic acid to the excipient, and formation of metal salts and caffeine hydrate. In compressed tablets with magnesium stearate, the cocrystal dissociation was readily discerned from the appearance of peaks attributable to caffeine hydrate and stearic acid. Neutral excipients provide an avenue to circumvent the risk of water mediated cocrystal dissociation.

The invention relates to the field of synthesis of organic chemistry, and discloses a synthetic method of caffeine. The method comprises that in the presence of a phase-transfer catalyst, theophylline or sodium theophylline and a methylation reagent of di

The invention relates to a preparation process for environment-friendly semisynthetic caffeine. According to the preparation process, preparation is carried out under the specific conditions like a temperature range of 90 to 160 DEG C, usage of an alkalin

6-Amino-1, 3-dimethyl-1H-pyrimidine-2, 4-dione 2 was prepared by alkylation of 6-amino-1H-pyrimidine-2, 4-dione 1 with methyl iodide. Formylation of 2 with formic acid afforded N-(1, 3-dimethyl-dioxo-tetrahydropyrimidin-4-yl)-formamide 3. The nitration of 3 gave N-(1,3-dimethyl-5-nitro-dioxo-tetrahydropyrimidin-4-yl) formamide 4. Reduction of 4 by zinc dust in glacial acetic acid yielded dimethyl-dihydro-purine-2, 6-dione 5. Addition of bromine to 2 leads to the formation of 6-amino-5-bromo-dimethyl-pyrimidine-2, 4-dione 7, cycloaddition of 7 with formamide afford the same product (theophylline 5), alkylated of 5 with methyl iodide to give caffeine 6. Reaction of 7 with glycine gave 2-(6-amino-dimethyl-dioxo-tetrahydropyrimidin-5-ylamino) acetic acid 8, refluxing of 8 with acetic acid /methanol gave dimethyl-dihydropyrimidopyrazine-trione 9, alkylation of 9 with alkyliodide afforded tetra-alkyldihydropyrimidopyrazine-trione 10a and 10b. The Cytotoxicity screen of the synthesized compounds was evaluated and the result showed that 10a, 10b, 9, 8, 7 and 6 exhibited highly potential antitumor activity.

Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083 bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.

Extract of cloudberries (Rubus chamaemorus) for use in agents for treating keratin fibers, particularly human hair, for improving the moisture in the fiber, repairing and restructuring the fibers and for protecting the fibers from oxidants and UV radiation, and for improving the color retention and color intensity when the fibers are colored hairs is disclosed.

The present invention provides a method of producing a co-crystal, the method comprising the steps of providing a first substance and a second substance, wherein the first and second substances are compatible to form a co-crystal, mixing said first and second substances together, and exposing the mixture of said first and second substances to prolonged and sustained conditions of pressure and shear, sufficient to form a co-crystal of said first and second substance. The prolonged and sustained conditions of pressure and shear are preferably applied in an extrusion process. Associated compositions and uses thereof are also provided.

A process for preparing theobromine by methylating 3-methyl xanthine disodium salt comprises reacting 3-methyl xanthine disodium salt with dimethyl sulfate by using acetone as solvent in the presence of sodium carbonate and acidifying. The present application also provides a process for refining theobromine which comprises dissolving coarse theobromine in liquid alkaline solution, decolorizing, filtering, adding reducing agent in filtrate, and acidifying at 60-80 °C until pH is 5-6, filtering, and drying to obtain theobromine.

The invention relates to hair treatment products, comprising at least one copolymer made of 0.1 to 50% (in relation to the total number of monomers in the copolymer) monomers of the formula (I), wherein the unknowns are defined as in claim 1, and A2) are monomers from the group of acrylic acid, methacrylic acid and the like, and—optionally non-ionic monomers from the group of acrylamide, vinyl alcohol, and the like, wherein the monomers A2 and A3 together represent 50 to 99.9% (in relation to the total number of monomers in the copolymer) of the copolymer, at least one silicon and at least one selected care product, wherein the products result in advantageous effects for skin and hair.

An inexpensive and novel method of caffeine synthesis starting from uracil in six simple steps is described. Uracil 1 is first converted to I, 3-dimethyluracil 2, followed by nitration, reduction, and cyclization to theophylline and finally methylation of theophylline forms caffeine.

The invention relates to the individualization of therapy on the basis of a phenotypic profile of an individual. More specifically, the present invention relates to the use of metabolic phenotyping for the individualization of treatment with the drug, amonafide.

The invention relates to the determination of multiple phenotypic determinants for human drug metabolizing enzymes. More specifically, the present invention relates to the characterization of metabolic phenotypes based on phenotypic determinants and applications and uses thereof.

The invention relates to the individualization of therapy on the basis of a phenotypic profile of an individual. More specifically, the present invention relates to the use of metabolic phenotyping for the individualization of treatment with the drug, amonafide.

New compounds of general formula I 1

Aqueous caffeine solutions containing a co-solubilizing agent selected from niacinamide, nicotinic acid and mixtures thereof present at a level up to the maximum concentration soluble in water and in a weight ratio to caffeine less than 1.50:1, wherein the caffeine is present up to the maximum level between about 2 and about 20 percent by weight that is water-soluble in combination with the co-solubilizing agent and the solution is buffered to a pH less than about 6. Methods for preparing the aqueous caffeine solutions of the present invention are also disclosed.

The synthesis of a cyclic homolog of caffeine is reported. Its 2-nitro- and 2-amino derivatives were obtained for the first time. It was shown that the 2-bromo and 2-chloro substituted cyclic homologs react with nucleophiles under basically identical conditions. Whereas 8-bromocaffeine can give a normal Ullman reaction product via heating with powdered copper in ethylene glycol, the homolog gives only a reduction product and does not react with potassium thiocyanate or cyanide. 1998 Plenum Publishing Corporation.

An imprint polymer having non covalent recognition sites for caffeine, capable of selectively removing caffeine from an aqueous extract derived from green or roasted coffee beans. A process for extracting caffeine from an aqueous extract derived from green or roasted coffee beans, in which the extract is contacted with an imprint polymer having non covalent recognition sites for caffeine and capable to selectively remove caffeine from an aqueous extract, whereby caffeine is removed from said extract. A cartridge containing an imprint polymer having non covalent recognition sites for caffeine for use to decaffeinate a coffee extract derived from roasted coffee beans.

2,6-Dialkoxy-7,9-dimethylpurinium iodides 1 undergo thermal transformation to 1,3,7-trialkylxanthines 2 as a result of C6O → Nx, C2O → NX, N9 → Nx, and N7 → Nx (when x = 1, 3 or 7) alkyl group migration. Intra-or intermolecular character of rearrangement was studied using deuterium-labelled derivatives of 1, and by cross-over experiment with salts 1a* and 1c. The 1H NMR spectra of 1,3,7-trialkylxanthines 2 (R = Me, Et) are presented.

There is provided a matrix preparation produced by dispersing a pharmaceutically active ingredient into a matrix which is solid at ambient temperature and comprised of a fatty acid ester of a polyglycerol. The preparation has stable release controlling ability, can be processed to fine granules, granules, capsules, tablets etc., and contributes to reduction of the administration times of the active ingredient and side effects of the ingredient.

The reaction of sodium or potassium thiolates with alkanols and carbon monoxide provides a versatile route to produce thioethers in excellent yields.By analogy, the potassium salt of theophylline suffers a nearly quantitative conversion to caffeine when heated with methanol under CO pressure.The mechanism of these alkylation reactions is discussed. - Key Words: Nucleophilic alkylation / Thioethers / Caffeine / Carbon monoxide / Alkanols

A general synthetic route to 3,7-dialkylxanthines (type 9) from 3,7-dialkyladenines (6) [hence from 3- or 7-alkyladenines (11 or 10)] has been established. The route started with ethoxycarbonylation of 1-alkyl-4-(alkylamino)1H-imidazole-5-carboxamides (7), readily obtainable from 6 by alkaline hydrolysis, and proceeded through cyclization of the resulting carbamates (8) under alkaline conditions. Alkylation of 9 with alkyl halide in N,N-dimethylformamide in the presence of anhydrous K2CO3 extended the above synthetic route to the 1,3,7-trialkylxanthine level (type 14). Hydrogenolytic deb nzylation of 3-benzyl-1,7-dimethylxanthine (16), prepared by following this general synthetic route, furnished paraxanthine (26) in fair yield. Conversion of 26 into 3-(4-hydroxy-3-nitrobenzyl)-1,7-dimethylxanthine (24), isomeric with the bryozoan purine phidolopin (2), was effected through aralkylation with 4-(methoxymethoxy)-3-nitrobenzyl bromide (28) followed by O-deprotection. On the basis of proton nuclear magnetic resonance data for the 3,7-dialkylxanthines (3 and 9b-i) and 1,3,7-trialkylxanthines (5 and 14-22) thus prepared, reliable criteria for distinguishing signals of N-alkyl substituents at various positions are put forward.

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In the aqueous liquid preparation of this invention, which comprises a compound of the formula; STR1 wherein R is an alkyl having 1-6 carbon atoms, and at least one species of the solubilizers selected from the group consisting of polyvinylpyrrolidone, cyclodextrin and caffeine, the solubility of the compound in water can be heightened and the aqueous liquid prepared thereby can afford a desired stability and mitigate eye-irritation or nose-irritation.

The previously unknown 9-aminotheophylline and 1-methyl-9-aminoxanthine were synthesized from 3-methyl-5-amino-6-hydrazinouracil.In the case of 1-methyl-9-aminoxanthine an x-ray diffraction study of an N-amino derivative of an NH heterocycle was made for the first time.

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N-Alkylation of imides with O-alkylisoureas has been found to accur under neutral conditions.Stereochemical data and structural factors indicate that an SN2 mechanism is operative.

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Caffeine adsorbed on caffeine adsorbents is recovered by contacting the carbon with a solvent, preferably an aqueous solution of ethylene carbonate or propylene carbonate. The caffeine adsorbent is contacted with the solvent for a period time sufficient to remove at least a portion of the caffeine adsorbed thereon and then separated from caffeine-containing solvent. The caffeine may be recovered from the solvent by precipitation.

A series of the title reagents have been used for the alkylation of a number of nucleophiles including iodide, cyanide, thiocyanate and fluoride ions as well as ethyl acetoacetate, phenylacetonitrile and a variety of nitrogen heterocyclic compounds.The results compared favorably with literature methods.

The isomerization or dealkylation of methylated xanthinium derivatives takes place with the participation of nucleophiles and is facilitated in the presence of a sterically hindered configuration.When heated, 7,9-dimethyl- and 1,7,9-trimethylxanthinium salts isomerize to theobromine and caffeine respectively.Under these conditions 3,7,9-trimethyl- and 1,3,7,9-tetramethylxanthinium salts are dealkylated.The 1,7,9- and 3,7,9-trimethylxanthinium betaines are isomerized quantitatively to caffeine.The role of the nucleophile under these conditions is played by the negatively charged fragment in the pyridine part of molecule.An intermolecular mechanism of rearrangement of the 3,7,9-trimethylxanthinium betaine is demonstrated.The sterically overloaded 1,3,8,9-tetramethylxanthine and 1,3,9-trimethyl-8-azaxanthine and not the charged compounds undergo rearrangement.In these cases the nucleophilic center is the doubly bonded N7 atom in the five-membered ring.

The B2E=constant linked scan is shown to be an excellent tool for quantifications with reversed geometry mass spectrometers.Deuterium-labelled analogues may be used as internal standards, thus providing very simple clean-up procedures.The principle is demonstrated with the example of chloro-substituted benzoic acid methyl esters.Possible interferences arising from isotope peaks are discussed.The method is applied to the quantification of caffeine in beverages.

Caffeine is prepared from theophylline, carbon monoxide and methanol.

The phase transfer catalysed methylation of adenine gave selectively 9-methyladenine (98percent), while benzylation yields 9-benzyladenine as the major product accompanied by very small amounts of the 3-isomer.Alkylation of xanthine, theobromine and theophylline by the same technique gave also the corresponding N.alkyl derivatives in high yields, with no other O-alkylated regioisomer.These alkylation procedures, owing to their simplicity and selectivity, constitute a considerable improvement upon classical techniques.

The photoreactions of stilbene and 1,4-diphenyl-1,3-butadiene with caffeine and of stilbene with benzothiazole, 1-methylimidazole and 2-(methylthio)benzothiazole have been investigated with respect to know (- , -cycloaddition , inserting -addition ), mechanistically new (uncatalyzed, substitutive -addition ) and principally new reaction types (substitutive -addition with substituent migration and cleavage of a double bond , substitutive -addition with cleavage of a double bond , intermolecular exchange of vinyl substituents ).The products are isolated and characterized analytically, spectroscopically (UV, 1H, 13C NMR) and by chemical transformations .The new reaction types are without precedence.They are formulated to occur via 1,4-diradicals.

Alumina coated with potassium fluoride promotes smooth N-alkylation of carboxamides, lactams, and other N-heterocycles with alkyl halides or dialkyl sulfate under mild conditions.

The object of the invention is to provide an improved process for recovering caffeine adsorbed on activated carbon. Caffeine removed from the commercial decaffeination of vegetable materials and extracts can be effectively removed from the extraction solvent, or can be purified, by the use of activated carbon. Unfortunately, the caffeine is tenaciously held by the carbon and none of the techniques currently available for removing the caffeine is wholly satisfactory. The recovery of caffeine from activated carbon is accomplished according to the present invention by employing a liquid, food-grade caffeine solvent which comprises an organic acid or alcohol, and which is capable of competing for the active sites on the carbon occupied by the caffeine to displace at least a portion of the caffeine which is then dissolved in the solvent. After the desired period of contact, the caffeine is separated from the solvent. The solvent will preferably comprise glacial acetic acid or an acetic acid azeotrope, and contact will preferably be at a temperature above 100° C.

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Alkyl halides react rapidly with purines and pyrimidines in the presence of fluoride ion. Alkylation of thymidine leads to novel dimeric nucleoside derivatives bridged through N3. Alkylation of thymidine mono and dinucleotides leads to alkylation at the base (N3) as well as diester and triester formation at the phosphate.

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