- A synthesis of atenolol using a nitrile hydration catalyst
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The synthesis of atenolol is described using a platinum containing homogeneous catalyst for the conversion of a nitrile to an amide. The catalytic reaction may be employed as the final step in the synthesis or in the preparation of the intermediate 4-hydroxyphenylacetamide. The structure of the nitrile intermediate, 1-(4′-cyanomethylphenoxy)-2-hydroxy-3-isopropylaminopropane, has been determined by X-ray crystallography.
- Akisanya, Joseph,Parkins, Adrian W.,Steed, Jonathan W.
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- Novel phenolic glycosides, adenophorasides A-E, from Adenophora roots
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Five novel phenolic glycosides, adenophorasides A (1), B (2), C (3), D (4), and E (5), were isolated from commercial Adenophora roots, together with vanilloloside (6), 3,4-dimethoxybenzyl alcohol 7-O-β-D-glucopyranoside (7), and lobetyolin (8). The structures of the new compounds (1-5) were characterized as 4-hydroxy-3-methoxyphenylacetonitrile 4-O-β-D- glucopyranoside (1), 4-hydroxy-3-methoxyphenylacetonitrile 4-O-β-D- glucopyranosyl-1→6)-b-D-glucopyranoside (2), 4-hydroxy-3- methoxyphenylacetonitrile 4-O-α-L-rhamnopyranosyl-(1→6)-β-D- glucopyranoside (3), 4-hydroxyphenylacetonitrile 4-O-β-D-glucopyranosyl- (1→6)-β-D-glucopyranoside (4),and 4-hydroxy-3-methoxybenzyl alcohol 4-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (5), respectively, by means of spectroscopic and chemical analyses. The Japanese Society of Pharmacognosy and Springer 2010.
- Koike, Yuka,Fukumura, Motonori,Hirai, Yasuaki,Hori, Yumiko,Usui, Shiho,Atsumi, Toshiyuki,Toriizuka, Kazuo
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- Cleavage of NH2 Terminal Tyrosyl-Peptide Bonds using Hypervalent Iodine
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The cleavage of NH2-tyrosine dipeptides with C6H5I(OAc)2-MeOH-KOH yields 4-(methoxymethyl)phenol.
- Moriarty, Robert M.,Sultana, Mumtaz,Ku, Yi-Yin
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- Direct C(sp3)-H Cyanation Enabled by a Highly Active Decatungstate Photocatalyst
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A highly efficient, direct C(sp3)-H cyanation was developed under mild photocatalytic conditions. The method enabled the direct cyanation of various C(sp3)-H substrates with excellent functional group tolerance. Notably, complex natural products and bioactive compounds were efficiently cyanated.
- Kim, Kunsoon,Lee, Seulchan,Hong, Soon Hyeok
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supporting information
p. 5501 - 5505
(2021/07/26)
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- Aryl phenol compound as well as synthesis method and application thereof
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The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
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Paragraph 0108-0111
(2021/05/12)
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- Lewis acid promoted dehydration of amides to nitriles catalyzed by [PSiP]-pincer iron hydrides
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The dehydration of primary amides to their corresponding nitriles using four [PSiP]-pincer hydrido iron complexes 1–4 [(2-Ph2PC6H4)2MeSiFe(H)(PMe3)2 (1), (2-Ph2PC6H4)2HSiFe(H)(PMe3)2 (2), (2-(iPr)2PC6H4)2HSiFe(H)(PMe3)2 (3) and (2-(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (4)] as catalysts in the presence of (EtO)3SiH as dehydrating reagent was explored in the good to excellent yields. It was proved for the first time that Lewis acid could significantly promote this catalytic system under milder reaction conditions than other Lewis acid-promoted system, such as shorter reaction time or lower reaction temperature. This is also the first example that dehydration of primary amides to nitriles was catalyzed by silyl hydrido iron complexes bearing [PSiP]-pincer ligands with Lewis acid as additive. This catalytic system has good tolerance for many substituents. Among the four iron hydrides 1 is the best catalyst. The effects of substituents of the [PSiP]-pincer ligands on the catalytic activity of the iron hydrides were discussed. A catalytic reaction mechanism was proposed. Complex 4 is a new iron complex and was fully characterized. The molecular structure of 4 was determined by single crystal X-ray diffraction.
- Chang, Guoliang,Li, Xiaoyan,Zhang, Peng,Yang, Wenjing,Li, Kai,Wang, Yajie,Sun, Hongjian,Fuhr, Olaf,Fenske, Dieter
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- An Air-Stable N-Heterocyclic [PSiP] Pincer Iron Hydride and an Analogous Nitrogen Iron Hydride: Synthesis and Catalytic Dehydration of Primary Amides to Nitriles
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An air-stable N-heterocyclic PSiP pincer iron hydride FeH(PMe3)2(SiPh(NCH2PPh2)2C6H4) (4) was synthesized by Si-H activation of a Ph-substituted [PSiP] pincer ligand. The analogous strong electron-donating iPr-substituted [PSiP] pincer ligand was prepared and introduced into iron complex to give an iron nitrogen complex FeH(N2)(PMe3)(SiPh(NCH2PiPr2)2C6H4) (6). Both 4 and 6 showed similar high efficiency for catalytic dehydration of primary amides to nitriles. Air-stable iron hydride 4 was the best catalyst for its stabilization and convenient preparation. A diverse range of cyano compounds including aromatic and aliphatic species was obtained in moderate to excellent yields. A plausible catalytic reaction mechanism was proposed.
- Fenske, Dieter,Fuhr, Olaf,Li, Xiaoyan,Sun, Hongjian,Wang, Yajie,Xie, Shangqing,Zhang, Hua
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- Efficient dehydration of primary amides to nitriles catalyzed by phosphorus-chalcogen chelated iron hydrides
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A series of phosphorus-chalcogen chelated hydrido iron (II) complexes 1–7, (o-(R'2P)-p-R-C6H4Y)FeH (PMe3)3 (1: R = H, R' = Ph, Y = O; 2: R = Me, R' = Ph, Y = O; 3: R = H, R' = iPr, Y = O; 4: R = Me, R' = iPr, Y = O; 5: R = H, R' = Ph, Y = S; 6: R = Me, R' = Ph, Y = S; 7: R = H, R' = Ph, Y = Se), were synthesized. The catalytic performances of 1–7 for dehydration of amides to nitriles were explored by comparing three factors: (1) different chalcogen coordination atoms Y; (2) R' group of the phosphine moiety; (3) R substituent group at the phenyl ring. It is confirmed that 5 with S as coordination atom has the best catalytic activity and 7 with Se as coordination atom has the poorest catalytic activity among complexes 1, 5 and 7. Electron-rich complex 4 is the best catalyst among the seven complexes and the dehydration reaction was completed by using 2 mol% catalyst loading at 60 °C with 24 hr in the presence of (EtO)3SiH in THF. Catalyst 4 has good tolerance to many functional groups. Among the seven iron complexes, new complexes 3 and 4 were obtained via the O-H bond activation of the preligands o-iPr2P(C6H4)OH and o-iPr2P-p-Me-(C6H4)OH by Fe(PMe3)4. Both 3 and 4 were characterized by spectroscopic methods and X-ray diffraction analysis. The catalytic mechanism was experimentally studied and also proposed.
- Li, Kai,Sun, Hongjian,Yang, Wenjing,Wang, Yajie,Xie, Shangqing,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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- Synthesis of Phenols: Organophotoredox/Nickel Dual Catalytic Hydroxylation of Aryl Halides with Water
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A highly effective hydroxylation reaction of aryl halides with water under synergistic organophotoredox and nickel catalysis is reported. The OH group of the resulting phenols originates from water, following deprotonation facilitated by an intramolecular base group on the ligand. Significantly, aryl bromides as well as less reactive aryl chlorides served as effective substrates to afford phenols with a wide range of functional groups. Without the need for a strong inorganic base or an expensive noble-metal catalyst, this process can be applied to the efficient preparation of diverse phenols and enables the hydroxylation of multifunctional pharmaceutically relevant aryl halides.
- Yang, Liu,Huang, Zhiyan,Li, Gang,Zhang, Wei,Cao, Rui,Wang, Chao,Xiao, Jianliang,Xue, Dong
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supporting information
p. 1968 - 1972
(2018/02/06)
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- Synthesis of α-aminonitriles using aliphatic nitriles, α-amino acids, and hexacyanoferrate as universally applicable non-toxic cyanide sources
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In cyanation reactions, the cyanide source is often directly added to the reaction mixture, which restricts the choice of conditions. The spatial separation of cyanide release and consumption offers higher flexibility instead. Such a setting was used for the cyanation of iminium ions with a variety of different easy-to-handle HCN sources such as hexacyanoferrate, acetonitrile or α-amino acids. The latter substrates were first converted to their corresponding nitriles through oxidative decarboxylation. While glycine directly furnishes HCN in the oxidation step, the aliphatic nitriles derived from α-substituted amino acids can be further converted into the corresponding cyanohydrins in an oxidative C-H functionalization. Mn(OAc)2 was found to catalyze the efficient release of HCN from these cyanohydrins or from acetone cyanohydrin under acidic conditions and, in combination with the two previous transformations, permits the use of protein biomass as a non-toxic source of HCN.
- Nauth, Alexander M.,Konrad, Tim,Papadopulu, Zaneta,Vierengel, Nina,Lipp, Benjamin,Opatz, Till
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supporting information
p. 4217 - 4223
(2018/09/29)
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- Porous conjugated polymer via metal-free synthesis for visible light-promoted oxidative hydroxylation of arylboronic acids
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Porous conjugated polymers have emerged recently as efficient metal-free and visible light-active photocatalysts. However, the synthesis of this new class of materials usually requires transition metal catalysts such as palladium. A metal-free synthetic route still remains a huge challenge for the chemists. Here we report on a metal-free pathway of a porous conjugated polymer via simple Knoevenagel polycondensation under mild reaction conditions. The obtained polymer exhibited a high surface area and could be applied as a robust and efficient heterogeneous photocatalyst for the oxidative hydroxylation of arylboronic acids under visible light irradiation with a high functional group tolerance of the substrates.
- Wang, Zi Jun,Li, Run,Landfester, Katharina,Zhang, Kai A.I.
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p. 291 - 295
(2017/09/15)
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- Technical Process for Preparation of Genistein
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Development and scale-up of the synthetic process for genistein preparation are described. The process was designed with consideration for environmental and economical aspects and optimized in a laboratory scale. In a scale up, on every step quantity of the environmentally unfriendly substrates or solvents was reduced without compromising the quality of the final product, and the waste load was significantly diminished. The optimal duration times of the individual stages were determined, and the number of operations was reduced, leading to lowering of energy consumption. Elaborated process secures good yield and quality expected for pharmaceutical substances.
- Filip, Katarzyna,Kleczkowska-Plichta, Ewa,Ara?ny, Zbigniew,Grynkiewicz, Grzegorz,Polowczyk, Magdalena,Gabarski, Krzysztof,Trzcińska, Kinga
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p. 1354 - 1362
(2016/07/23)
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- Demethylation of aromatic methyl ethers using ionic liquids under microwave irradiation
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An efficient demethylation reaction for aromatic methyl ethers has been developed. Deprotection reactions give high yields with butylpyridinium bromide under microwave irradiation. Basic and acidic functional groups are tolerated if the reaction is performed under acidic conditions.
- Passiniemi, Mikko,Myllymaeki, Mikko J.,Vuokko, Juha,Koskinen, Ari M.P.
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scheme or table
p. 48 - 52
(2012/04/10)
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- The first total synthesis of aplysamine 6, an inhibitor of isoprenylcysteine carboxy methyltransferase
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The first total synthesis of aplysamine 6, an inhibitor of isoprenylcysteine carboxy methyltransferase (Icmt), was accomplished in an overall high yielding reaction sequence.
- Ullah, Nisar,Arafeh, Khaled M.
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scheme or table
p. 158 - 160
(2009/04/14)
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- NOVEL PROCESS FOR PREPARATION OF O-DESMETHYLVENLAFAXINE
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The present invention relates to the novel processes for the preparation of 4-(2- (dimethylamino)-1-(1-hydroxycyclohexyl)ethyl)phenol, commonly known as O- desmethylvenlafaxine of formula (I) and its pharmaceutically acceptable salts thereof The present invention also relates to the novel process for the preparation of O- desmethylvenlafaxine of formula (I) and its pharmaceutically acceptable salts thereof formula (V) or formula (VI) formula (I) or formula (VII) wherein, R is hydrogen, methoxyethoxymethyl (MEM), methoxymethyl (MOM), aryloyl, arylsulfonyl, tetrahydropyranyl or substituted silyl.
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Page/Page column 7; 8; 18-19
(2009/08/14)
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- 1,3-Diethynylallenes: Stable monomers, length-defined oligomers, asymmetric synthesis, and optical resolution
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A series of differently substituted 1,3-diethynylallenes (DEAs) have been synthesized, confirming that the previously introduced construction protocols tolerate a variety of functional groups. The new DEAs bear at least one polar group to facilitate enantiomer separations on chiral stationary phases and to allow further functionalization. They are thermally and environmentally stable compounds since bulky substituents next to the cumulene moiety suppress the tendency to undergo [2+2] cyclodimerization. A series of length-defined oligomers were obtained as mixtures of stereoisomers by oxidative coupling of a monomeric DEA under Glaser-Hay conditions. The electronic absorption data indicate a lack of extended π-electron conjugation across the oligomeric backbone due to the orthogonality of the allenic π-systems. Remarkably, even complex mixtures of stereoisomers only yield one single set of NMR signals, which underlines the low stereodifferentiation in acyclic allenoacetylenic structures. Optical resolution of DEAs represents an amazing challenge, and preliminary results on the analytical level are reported. Asymmetric synthesis by Pd-mediated SN2′-type cross-coupling of an alkyne to an optically pure bispropargylic precursor opens another promising route to optically active allenes with stereoselectivities currently reaching up to 78 % ee. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Ter Wiel, Matthijs K. J.,Odermatt, Severin,Schanen, Patrick,Seiler, Paul,Diederich, Francois
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p. 3449 - 3462
(2008/02/12)
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- Enhanced O-dealkylation activity of SiCl4/LiI with catalytic amount of BF3
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Dibenzyloxydihydrobenzoxathiin 1, which resisted debenzylation with SiCl4/LiI, was effectively debenzylated with SiCl4/LiI in the presence of a catalytic amount of BF3. The HCl salt of the bis-debenzylated product 2 was isolated in 90% yield and 99% purity. This enhanced dealkylation activity has also been observed with other substrates.
- Zewge, Daniel,King, Anthony,Weissman, Steven,Tschaen, David
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p. 3729 - 3732
(2007/10/03)
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- Microwave assisted dealkylation of alkyl aryl ethers in ionic liquids
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Alkyl aryl ethers undergo selective dealkylation in 1-butyl pyridinium bromide and 1-butyl-3-methyl imidazolium bromide ionic liquids under microwave irradiation to give the corresponding phenols in high yields. The ionic liquids serve the dual purpose of solvent as well as reagent and allow easy isolation of products.
- Chauhan, Shive M. S.,Jain, Nidhi
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p. 693 - 694
(2007/10/03)
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- High-temperature rearrangements of 2-acylisoxazol-5(2H)-ones and related oxazoles
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2-Acyl-3-arylisoxazol-5(2H)-ones give 2-alkyl(aryl)-4-aryloxazoles in good yields at 540°C under flash vacuum pyrolysis conditions, but at higher temperatures the expected oxazoles are accompanied by increasing amounts of isomeric 2,5-disubstituted oxazoles, as well as anilides and decomposition products of the 2,4-disubstituted oxazole. The rearrangement mechanisms have been studied by the use of 13C labelled substrates and p-substituted 3-arylisoxazolones. The 2,5-disubstituted oxazoles are considered to arise from 1H-azirines, and the anilides from the nitrone ketene isomer of the acylisoxazolone.
- Clark, Adrian D.,Ha, Uyen T.,Prager, Rolf H.,Smith, Jason A.
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p. 1029 - 1033
(2007/10/03)
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- Liquid Crystalline trans-4-(ω-Cyanalkyl)cyclohexylester and 4-(ω-Cyanalkyl)phenylesters
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The synthesis of the title esters 1 and 2a-e (n = 0-3) and their mesomorphic properties are described.When the alkyl-spacer n between the polar CN-group and the cyclohexane ring of cyanalkyl-cyclohexylesters 1 is increased the difference of the clearing points between the phenylesters 2 and the cyclohexylesters 1 decreases to nearly zero.The reason of higher clearing temperatures of 2 is a dynamic conformational effect of ring inversion of cyclohexane in the ester 1 with two polar substituents at the ring.
- Deutscher, H.-J.,Krieg, R.,Frach, R.,Kresse, H.,Zaschke, H.
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p. 963 - 974
(2007/10/02)
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- Method of preparing 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenols
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4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-hydrocarbyl-substituted phenols having the formula STR1 wherein R1 and R2 are the same or different monovalent substituents selected from the group consisting of alkyl, aralkyl and cyclic alkyl radicals and R3 is selected from hydrogen, hydrocarbyl radicals, substituted hydrocarbyl radicals and hydrocarbyloxy radicals are prepared by reacting an N,N-di-hydrocarbyl-4-(α-hydrocarbyl-α-aminomethyl)2,6-di-hydrocarbyl-substituted phenol having the formula STR2 wherein R1, R2 and R3 are as defined above and R4 and R5 are the same or different and are selected from hydrogen, hydrocarbyl radicals and substituted hydrocarbyl radicals with an alkali metal cyanide or an alkaline earth metal cyanide in a suitable solvent. The 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenol thus formed can readily be converted to the corresponding 4-(α-hydrocarbyl-α-cyanomethyl)phenol by dealkylating the substituent groups ortho to the hydroxyl group from the 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenol which then can be converted on hydrolysis to the corresponding α-hydrocarbyl-4-hydroxyphenylacetic acid. These acids have utility as insecticidal and acaricidal intermediates and are deemed to have utility as insecticides themselves as are the 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenols of the present invention.
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- Preparation of 4-(α-hydrocarbyl-α-cyanomethyl)-2,6-di-substituted phenols
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4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenols having the formula STR1 wherein R1 and R2 are the same or different monovalent substituents selected from the group consisting of alkyl, aralkyl and cyclic alkyl radicals and R3 is selected from hydrogen, hydrocarbyl radicals, substituted hydrocarbyl radicals and hydrocarbyloxy radicals are prepared by reacting a 4-(α-hydrocarbyl-α-hydrocarbyloxymethyl)2,6-di-substituted phenol having the formula STR2 wherein R1, R2 and R3 are as defined above and R4 is selected from hydrocarbyl radicals or substituted hydrocarbyl radicals with an alkali metal cyanide or an alkaline earth metal cyanide in a suitable solvent. The 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenol thus formed can readily be converted to the corresponding 4-(α-hydrocarbyl-α-cyanomethyl)phenol by dealkylating the substituent groups ortho to the hydroxyl group from the 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenol which then can be converted on hydrolysis to the corresponding α-hydrocarbyl-4-hydroxyphenylacetic acid. These acids have utility as insecticidal and acaricidal intermediates and are deemed to have utility as insecticides themselves as are the 4-(α-hydrocarbyl-α-cyanomethyl)2,6-di-substituted phenols of the present invention.
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- Process for the manufacture of aromatic cyanides
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The invention provides a process for the preparation of ortho- and para-hydroxybenzyl cyanides. The process of the invention comprises the reaction of an aromatic alcohol selected from ortho- and para-hydroxybenzyl alcohols with a cyanide reagent and an ester capable of esterifying the hydroxyl group of the benzyl alcohol. In a preferred form of the process there is employed a route via the reaction of an ortho- or para-hydroxybenzyl formate with a cyanide reagent preferably selected from sodium and potassium cyanides.
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- Process for the manufacture of p-hydroxybenzyl cyanide
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An improved process for the preparation of p-hydroxybenzyl cyanide by the reaction of p-hydroxybenzyl alcohol with an alkali metal cyanide, by carrying out the process in the presence of an alkyl formate, especially n-propyl formate. The cyanide product is a valuable intermediate for the preparation of the β-adrenergic blocking agent atenolol.
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- Process for the manufacture of p-hydroxybenzyl cyanide
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A process for the manufacture of p-hydroxybenzyl cyanide which comprises reacting p-hydroxyphenylglycine acid with cyanide ion. The product is a useful intermediate for the preparation of the β-adrenergic blocking agent atenolol.
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- Immonium salts and derivatives thereof
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There are provided: novel aryloxy immonium salts, prepared by the reaction of their corresponding haloformates with amides; and phenolic compositions corresponding to the aryloxy immonium salts. These novel aryloxy immonium salts and their corresponding phenolic compositions have utility as chemical intermediates, antioxidants, stabilizers and antibacterials.
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- Process for the preparation of hydroxyphenylacetonitriles
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Hydroxyphenylacetonitriles, which are known chemical intermediates, are prepared by the reaction of hydroxybenzyl alcohols and hydrogen cyanide. A representative example is the preparation of 3-methoxy-4-hydroxyphenylacetonitrile from 3-methoxy-4-hydroxybenzyl alcohol and hydrogen cyanide.
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- Immonium salts and derivatives thereof
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There are provided: novel aryloxy immonium salts, prepared by the reaction of their corresponding haloformates with amides; and phenolic compositions corresponding to the aryloxy immonium salts. These novel aryloxy immonium salts and their corresponding phenolic compositions have utility as chemical intermediates, antioxidants, stabilizers and antibacterials.
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