- Preparation method of (S)-4- (C)-3-(S)-bromopyridine (bromopyridine) (by machine translation)
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The method disclosed by the invention has, the beneficial, effects :(1) that 4 - the reaction conditions are mild, the treatment is easy 4 - the method is easy to, operate, the, treatment, is easy . and the method is, easy to, operate 4 - and easy to ;(2) operate 4 - pH, 4 . (by machine translation)
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Paragraph 0017-0018; 0020-0021; 0023-0024
(2020/02/19)
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- Low-cost simple and convenient preparation method of 3-amino-4-methylpyridine
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The invention relates to a low-cost simple and convenient preparation method of 3-amino-4-methylpyridine. The method comprises the following steps: performing addition on halogenated crotonaldehyde asa raw material and nitromethane, performing methylenenation condensation, performing aminopyridine cyclization to obtain 4-methyl-3-nitropyridine, and performing reduction to prepare the 3-amino-4-methylpyridine. According to the preparation method provided by the invention, the raw materials used in the method are cheap and easy to obtain, the conditions are mild, the operation is simple, convenient and safe, the reaction selectivity is high, the product yield and purity are high, and the costs are low; and in the process, the atomic economy is high, and three waste (waste water, waste gas and solid waste) is less.
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- A 4 - methyl -3 - bromo pyridine preparation method
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The invention belongs to the field of organic synthesis, in particular to a 4 - methyl - 3 - bromo pyridine method, comprises the following steps: (1) to 4 - methyl - 3 - nitro pyridine as raw materials, methanol as solvent, under the effects of catalyst hydrogenation reduction, filtered, the filtrate is concentrated, be 4 - methyl - 3 - aminopyridine; (2) the 4 - methyl - 3 - aminopyridine reacts with acid to form the salt cooling to - 10 °C - 0 °C, [...], [...] sodium nitrite aqueous solution, pH adjusting solution is dropped is alkaline, and then extracted, drying, concentration, a 4 - methyl - 3 - bromo pyridine. The beneficial effect of the invention is: mild reaction conditions, is easy to operate, after treatment is simple, and easy to enlarge production, is extremely suitable for industrial production; good catalytic effect, high yield; low prices of raw materials, the production cost is low.
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Paragraph 0014; 0017; 0018; 0020; 0021; 0023; 0024
(2019/06/05)
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- Copper(ii)-catalyzed c-n coupling of aryl halides and n-nucleophiles promoted by quebrachitol or diethylene glycol
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Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-Arylation of various amines and related aryl halides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C-N coupling reactions proceed under mild conditions and exhibit good functional group tolerance.
- Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Fu, Yang,Wu, Ying,Zhou, Qifan
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supporting information
p. 2161 - 2168
(2019/11/25)
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- Preparation method for nevirapine intermediate
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The invention relates to a preparation method for an intermediate, i.e., 2-chloro-3-amino-4-methylpyridine, of an anti-AIDs drug nevirapine. The intermediate has a chemical structural formula I as described in the specification. The preparation method is characterized in that 4-methylpyridine is subjected to halogenation, ammonia substitution and chlorination so as to prepare 2-chloro-3-amino-4-methylpyridine. The preparation reactions are as shown in the specifications, wherein X is bromine or chlorine; a halogenation condition is Br2/AlCl3/95-105 DEG C, Br2/AlCl3/MBr/110 to 130 DEG C (wherein M is Li, Na or K), Br2/Fe/135-145 DEG C, Cl2/AlCl3, Br2/FeCl3 or Br2/SnCl4; an ammonia substitution condition is NH3(g)/CuSO4/CH3OH/170-190 DEG C, NH3(aq)/CuSO4/170-190 DEG C, or NaNH2; and a chlorination reaction condition is Cl2/AlCl3 or HCl/H2O2/30-50 DEG C.
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Paragraph 0070-0072
(2017/05/27)
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- A 3-amino-4-methylpyridine preparation method
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The invention belongs to the field of organic chemical synthesis and particularly relates to a synthesis method of 3-amino-4-methylpyridine which is an intermediate of an anti-AIDS drug nevirapine. According to the method, 4-methylpyridine-3-boronic acid is used as a raw material, an inorganic amide is used as an ammonia source and obtain3-amino-4-methylpyridine is prepared through one-step reaction in the presence of metal oxide as a catalyst. The preparation method is still simple and provides a new way for novel and efficient synthesis of 3-amino-4-methylpyridine and the disadvantages of long traditional route, low yield and severe reaction conditions are overcome.
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Paragraph 0019-0020
(2017/04/27)
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- Synthesis of some fluorine-containing pyridinealdoximes of potential use for the treatment of organophosphorus nerve-agent poisoning
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Fluoroheterocyclic aldoximes were screened as therapeutic agents for the treatment of anticholinesterase poisoning. 2-Fluoropyridine-3- and -6-aldoxime, and 3-fluoropyridine-2- and -4-aldoxime, were synthesised. Attempts to obtain 3,5,6-trifluoropyridine-2,4-bis(aldoxime) and -2-aldoxime, however, proved unsuccessful. Pentafluorobenzaldoxime was prepared by oximation of pentafluorobenzaldehyde. Acid dissociation constants (pKa) and second-order rate constants (kox-) of the fluorinated pyridinealdoximes towards sarin were measured. 2,3,5,6-Tetrafluoropyridine-4- aldoxime had the best profile: its kox- approached that of the therapeutic oxime P2S (310 vs. 120 l mol-1 min-1), but its higher pKa (9.1 vs. 7.8) fell short of the target figure of 8 required for reactivation of inhibited acetylcholinesterase in vivo. N-alkylation of the fluorinated pyridine-aldoximes may reduce their pK a nearer to 8 and enhance their therapeutic potential. Crown Copyright
- Timperley, Christopher M.,Banks, R. Eric,Young, Ian M.,Haszeldine, Robert N.
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scheme or table
p. 541 - 547
(2011/09/15)
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- Rapid reduction of heteroaromatic nitro groups using catalytic transfer hydrogenation with microwave heating
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A method for the rapid, safe reduction of heteroaromatic and aromatic nitro groups to amines is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C or Pt/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In the case of substrates containing potentially labile aromatic halogens, Pt/C is effective and results in little or no dehalogenation. In general, the reactions are complete within 5 min at 120 °C.
- Quinn, John F.,Bryant, Cole E.,Golden, Kathryn C.,Gregg, Brian T.
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experimental part
p. 786 - 789
(2010/03/24)
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- Reduction of 2-amino-3- and -5-nitropyridine derivatives with hydrazine hydrate
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The reactions of 2-amino-3-nitropyridine and 2-amino-5-nitropyridine with hydrazine hydrate resulted in elimination of the amino group and reduction of the nitro group with formation of 3-aminopyridine. A probable reaction mechanism involves addition of hydrazine hydrate at the N-C2 bond, followed by elimination of ammonia and reduction of the nitro group to amino. 2-Amino-4-methyl-3-nitropyridine and 2-amino-5-methyl-3-nitropyridine reacted with hydrazine hydrate in a similar way.
- Smolyar,Yutilov
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experimental part
p. 115 - 118
(2009/07/19)
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- Heterocyclic substituted aminoazacycles useful as central nervous system agents
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Heterocyclic substituted aminoazacyclic compounds of the formula (I):Z-R3, wherein Z is a defined aminoazacycle and R3 is a defined heterocycle moiety, pharmaceutical compositions of these compounds, and use of said compositions to control synaptic transmission in mammals.
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- Diazabicyclic central nervous system active agents
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Compounds of formula I pharmaceutical compositions of these compounds, and use of said compositions to control synaptic transmission in mammals.
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- Inhibitors of protein isoprenyl transferases
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Compounds having the formula or a pharmaceutically acceptable salt thereof wherein R1 is (a) hydrogen, (b) loweralkyl, (c) alkenyl, (d) alkoxy, (e) thioalkoxy, (f) halo, (g) haloalkyl, (h) aryl-L2—, and (i) heterocyclic-L2—; R2 is selected from (a) (b) —C(O)NH—CH(R14)—C(O)OR15, (c) (d) —C(O)NH—CH(R14)—C(O)NHSO2R16 (e) —C(O)NH—CH(R14)-tetrazolyl, (f) —C(O)NH-heterocyclic, and (g) —C(O)NH—CH(R14)—C(O)NR17R18; R3 is heterocyclic, aryl, substituted or unsubstituted cycloalkyl; R4 is hydrogen, lower alkyl, haloalkyl, halogen, aryl, arylakyl, heterocyclic, or (heterocyclic)alkyl; L1 is absent or is selected from (a) —L4—N(R5)—L5—, (b) —L4—O—L5—, (c) —L4—S(O)n—L5— (d) —L4-L6—C(W)—N(R5)—L5—, (e) —L4-L6—S(O)m—N(R5)—L5—, (f) —L4—N(R5)—C(W)—L7-L5—, (g) —L4—N(R5)—S(O)p—L7—L5—, (h) optionally substituted alkylene, (i) optionally substituted alkenylene, and (j) optionally substituted alkynylene are inhibitors of protein isoprenyl transferases. Also disclosed are protein isoprenyl transferase inhibiting compositions and a method of inhibiting protein isoprenyl transferases.
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- Preparation of 4-substituted 3-amino-2-chloropyridines, synthesis of a nevirapine analogue
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A new method for preparing 3-amino-2-chloropyridines with a substituent (methyl, phenyl, carboxamide, methoxycarbonyl, acetyl, benzoyl and cyano) at the 4-position has been developed. An isoquinoline analogue of the reverse transcriptase inhibitor Nevirapine has been synthesized from the 4-amino-3-chloroisoquinoline.
- Bakke,Riha
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- Method for the preparation of 3-amino-2-chloro-4-methylpyridines
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A process for the preparation of a 3-amino-2-chloro-4-alkylpyridine of the formula: STR1 wherein R is alkyl of from one to three carbon atoms, an intermediate in the preparation of certain 5,11-dihydro-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepine compounds useful in the prevention and treatment of HIV infection.
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- Synthesis of nevirapine and its major metabolite
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Several synthetic methods were developed during the process optimization for the large scale synthesis of nevirapine (1), a non-nucleoside inhibitor of HIV-1 Reverse Transcriptase. The synthesis of its putative major metabolite 11-cyclopropyl-5,11-dihydro-4-hydroxymethyl-6H-[3,2-b:2',3'-e][1,4]dia zepin-6-one (2) and the oxidation of 2 to the corresponding aldehyde 3, are described.
- Grozinger,Fuchs,Hargrave,Mauldin,Vitous,Campbell,Adams
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p. 259 - 263
(2007/10/02)
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- Substituted fused pyrazolo compounds
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Novel substituted pyrazolo-rings fused to nitrogen containing heterocyclic rings having the following formula STR1 in which at least one of Y, Z or W is N or N-O and the remainder of Y, Z or W is C-R wherein the variables are as defined in the specification; and agriculturally acceptable salts thereof.
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- Method for preparing 3-amino-2-chloro-4-alkylpyridines
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A process for the preparation of a 3-amino-2-chloro-4-alkylpyridine of the formula: STR1 wherein R is alkyl of from one to three carbon atoms, an intermediate in the preparation of certain 5,11-dihydro-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepine compounds useful in the prevention and treatment of HIV infection.
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- The ortho effect in pyridines. Part XI(1). Substituent effects on basicity of 2- and 4-substituted 3-aminopyridines
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The substituent effects on the pKa values corresponding to the first protonation site of thirty 2- and 4-substituted 3-aminopyridines have been studied.It was found that the relative localized and delocalized effects are apparently sensitive to the variation of substituent position in the pyridine ring.An interaction of the 2-substituent with the protonation centre has mainly inductive character, whereas, the pKa values of 4-substituted 3-aminopyridines are highly affected by through-resonance.The steric effect was found to be insignificant.Keywords: substituent effects / 2- and 4-substituted 3-aminopyridines / basicity
- Rasala, D.
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- Studies on 1,3-Benzoxazines. II. New Rearrangement Modes in the Reaction of 4-Chloro-2,2-dimethyl-2H-1,3-benzoxazine with Substituted Pyridine N-Oxides
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New rearrangement modes in the reaction of 4-chloro-2,2-dimethyl-2H-1,3-benzoxazine (1) with various α- and/or γ-substituted pyridine N-oxides are described.The benzoxazine moiety was introduced into the side chain and/or β-position of the pyridine ring, in addition to the α-position.Possible mechanism of the reactions are discussed.Keywords - 1,3-benzoxazine; picoline N-oxide; lutidine N-oxide; imidoyl chloride; rearrangement.
- Wachi, Kazuyuki,Terada, Atsusuke
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p. 3020 - 3028
(2007/10/02)
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