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Tropinone
Tropinone is an alkaloid, famously synthesised in 1917 by Robert Robinson as a synthetic precursor to atropine, a scarce commodity during World War I. Tropinone and the alkaloids cocaine and atropine all share the same tropane core structure. Its corresponding conjugate acid at pH 7.3 major species is known as tropiniumone. Synthesis The first synthesis of tropinone was by Richard Willstätter in 1901. It started from the seemingly related cycloheptanone, but required many steps to introduce the nitrogen bridge; the overall yield for the synthesis path is only 0.75%. Willstätter had previously synthesized cocaine from tropinone, in what was the first synthesis and elucidation of the structure of cocaine. Robinson's "double Mannich" reaction The 1917 synthesis by Robinson is considered a classic in total synthesis due to its simplicity and biomimetic approach. Tropinone is a bicyclic molecule, but the reactants used in its preparation are fairly simple: succinaldehyde, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Robinson (organic Chemist)
Sir Robert Robinson (13 September 1886 – 8 February 1975) was a British organic chemist and List of Nobel laureates, Nobel laureate recognised in 1947 for his research on plant dyestuffs (anthocyanins) and alkaloids. In 1947, he also received the Medal of Freedom (1945), Medal of Freedom with Silver Palm. Biography Early life He was born at Rufford House Farm, near Chesterfield, Derbyshire, Chesterfield, Derbyshire the son of James Bradbury Robinson, a maker of surgical dressings, and his wife, Jane Davenport. Robinson went to school at the Brookfield Community School, Chesterfield, Chesterfield Grammar School and the private Fulneck School. He then studied chemistry at the Victoria University of Manchester, University of Manchester, graduating BSc in 1905. In 1907 he was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851 to continue his research at the University of Manchester. He was appointed as the first Professor of Pure and App ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthetic Equivalent
Retrosynthetic analysis is a technique for solving problems in the planning of organic syntheses. This is achieved by transforming a target molecule into simpler precursor structures regardless of any potential reactivity/interaction with reagents. Each precursor material is examined using the same method. This procedure is repeated until simple or commercially available structures are reached. These simpler/commercially available compounds can be used to form a synthesis of the target molecule. Retrosynthetic analysis was used as early as 1917 in Robinson's Tropinone total synthesis. Important conceptual work on retrosynthetic analysis was published by George Vladutz in 1963. E.J. Corey formalized and popularized the concept from 1967 onwards in his article ''General methods for the construction of complex molecules'' and his book ''The Logic of Chemical Synthesis''. The power of retrosynthetic analysis becomes evident in the design of a synthesis. The goal of retrosynthetic ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocaine
Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated almost exclusively in the Andes. Indigenous peoples of South America, Indigenous South Americans have traditionally used coca leaves for over a thousand years. Notably, there is no evidence that habitual coca leaf use causes addiction or withdrawal, unlike cocaine. Medically, cocaine is rarely employed, mainly as a topical medication under controlled settings, due to its high abuse potential, adverse effects, and expensive cost. Despite this, recreational drug use, recreational use is widespread, driven by its euphoric and aphrodisiac properties. Levamisole induced necrosis syndrome (LINES)-a complication of the common cocaine Lacing (drugs), cutting agent levamisole-and prenatal cocaine exposure is particularly harmful. Street cocaine is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tandem Reaction
A cascade reaction, also known as a domino reaction or tandem reaction, is a chemical process that comprises at least two consecutive reactions such that each subsequent reaction occurs only in virtue of the chemical functionality formed in the previous step.Tietze, L. F.; Beifuss, U. ''Angew. Chem. Int. Ed.'' 1993, ''32'', 131–163. In cascade reactions, isolation of intermediates is not required, as each reaction composing the sequence occurs spontaneously. In the strictest definition of the term, the reaction conditions do not change among the consecutive steps of a cascade and no new reagents are added after the initial step.Padwa, A.; Bur, S. K. ''Tetrahedron'' 2007, ''63'', 5341–5378. By contrast, one-pot procedures similarly allow at least two reactions to be carried out consecutively without any isolation of intermediates, but do not preclude the addition of new reagents or the change of conditions after the first reaction. Thus, any cascade reaction is also a one-pot p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloheptanone
Cycloheptanone, (CH2)6CO, is a cyclic ketone also referred to as suberone. It is a colourless volatile liquid. Cycloheptanone is used as a precursor for the synthesis of pharmaceuticals. Synthesis In 1836, French chemist Jean-Baptiste Boussingault first synthesized cycloheptanone from the calcium salt of dibasic suberic acid. The ketonization of calcium suberate yields calcium carbonate and suberone: :Ca(O2C(CH2)6CO2) → CaCO3 + (CH2)6CO Cycloheptanone is still produced by the cyclization and decarboxylation of suberic acid or suberic acid esters. This reaction is typically conducted in the gas phase at 400–450 °C over alumina doped with zinc oxide or cerium oxide. Cycloheptanone is also produced by the reaction of cyclohexanone with sodium ethoxide and nitromethane. The resulting sodium salt of 1-(nitromethyl)cyclohexanol is added to acetic acid and shaken with hydrogen gas in the presence of W-4 Raney nickel catalyst. Sodium nitrite and acetic acid are then added to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activating Group
In electrophilic aromatic substitution reactions, existing substituent groups on the aromatic ring influence the overall reaction rate or have a directing effect on positional isomer of the products that are formed. An electron donating group (EDG) or electron releasing group (ERG, Z in structural formulas) is an atom or functional group that donates some of its electron density into a conjugated π system via resonance (mesomerism) or inductive effects (or induction)—called +M or +I effects, respectively—thus making the π system more nucleophilic. As a result of these electronic effects, an aromatic ring to which such a group is attached is more likely to participate in electrophilic substitution reaction. EDGs are therefore often known as activating groups, though steric effects can interfere with the reaction. An electron withdrawing group (EWG) will have the opposite effect on the nucleophilicity of the ring. The EWG removes electron density from a π system, making ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Solution
A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean. Principles of buffering Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−: When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Medicinal Chemistry
The ''Journal of Medicinal Chemistry'' is a biweekly peer-reviewed medical journal covering research in medicinal chemistry. It is published by the American Chemical Society. It was established in 1959 as the ''Journal of Medicinal and Pharmaceutical Chemistry'' and obtained its current name in 1963. Philip S. Portoghese served as editor-in-chief from 1972 to 2011. In 2012, Gunda Georg (University of Minnesota) and Shaomeng Wang (University of Michigan) succeeded Portoghese (University of Minnesota). In 2021, Craig W. Lindsley (Vanderbilt University) became editor-in-chief. According to the ''Journal Citation Reports'', the journal has a 2023 impact factor of 7.1. See also *ACS Medicinal Chemistry Letters ''ACS Medicinal Chemistry Letters'' is a monthly peer-reviewed scientific journal covering medicinal chemistry. It was established in 2009 and is published by the American Chemical Society. The editor-in-chief is Dennis C. Liotta (Emory University ... References External ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetonedicarboxylic Acid
Acetonedicarboxylic acid, 3-oxoglutaric acid or β-ketoglutaric acid is a simple dicarboxylic acid with the formula . β-Ketoglutarate does not have the biological activity exhibited by α-ketoglutarate. Preparation Acetonedicarboxylic acid can also be prepared by decarboxylation of citric acid in fuming sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...: : Applications Acetonedicarboxylic acid and its esters such as dimethylacetonedicarboxylate are primarily used as building blocks in the synthesis of heterocyclic rings and in the Weiss–Cook reaction. Acetonedicarboxylic acid is well known to be used in the Robinson tropinone synthesis. The presence of β-ketoglutaric acid in human urine is diagnostic for the harmful gut flora such as '' Candida albicans' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannich Reaction
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). The final product is a β-amino-carbonyl compound also known as a Mannich base. Reactions between aldimines and α-methylene carbonyls are also considered Mannich reactions because these imines form between amines and aldehydes. The reaction is named after Carl Mannich. The Mannich reaction starts with the nucleophilic addition of an amine to a carbonyl group followed by dehydration to the Schiff base. The Schiff base is an electrophile which reacts in a second step in an electrophilic addition with an enol formed from a carbonyl compound containing an acidic alpha-proton. The Mannich reaction is a condensation reaction. In the Mannich reaction, primary or secondary amines or ammonia react with formaldehyde to form a Schiff base. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robinson Tropinone Synthesis
Robinson may refer to: People and names * Robinson (name) Fictional characters * Robinson Crusoe, the main character, and title of a novel by Daniel Defoe, published in 1719 Geography * Robinson projection, a map projection used since the 1960s to show the entire world in two dimensions * Robinson (crater), a small lunar impact crater southwest of the large walled plain J. Herschel ;United States * Robinson, Illinois * Robinson, Iowa * Robinson, Kansas * Robinson, Kentucky * Robinson, Minnesota * Robinson, North Dakota * Robinson, Texas * Robinson Township, Allegheny County, Pennsylvania * Robinson Township, Washington County, Pennsylvania * Robinson, Indiana County, Pennsylvania ;United Kingdom * Robinson (Lake District), a 737 m hill in England's Lake District * Robinson College, Cambridge, a college in England's University of Cambridge ;France * Robinson (Paris RER), a commuter train station in Paris Ships * USS ''Robinson'', the name of more than one United States N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One-pot Synthesis
In chemistry a one-pot synthesis is a strategy to improve the efficiency of a chemical reaction in which a reactant is subjected to successive chemical reactions in just one reactor. This is much desired by chemists because avoiding a lengthy separation process and purification of the intermediate chemical compounds can save time and resources while increasing chemical yield. An example of a one-pot synthesis is the total synthesis of tropinone or the Gassman indole synthesis. Sequential one-pot syntheses can be used to generate even complex targets with multiple stereocentres, such as oseltamivir, which may significantly shorten the number of steps required overall and have important commercial implications. A sequential one-pot synthesis with reagents added to a reactor one at a time and without work-up is also called a telescoping synthesis. In one such procedure the reaction of 3-N-tosylaminophenol I with acrolein II affords a hydroxyl substituted quinoline III thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
