- Synthesis method of carbonyl alpha-position monomethyl substituted compound
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The invention discloses a synthesis method of a carbonyl alpha-position monomethyl substituted compound, thesynthesis method comprises the following steps: taking substituted phenylboronic acid and ethyl 2-bromoacrylate as raw materials, taking THF and water as solvents, reacting K2CO3 and a catalyst Pd (OAc) 2 under the protection of nitrogen, purifying to obtain an intermediate product, dissolving the intermediate product in a methanol solvent, performing catalytic hydrogenation, reacting at room temperature, filtering, and spin-drying the solvent to obtain the carbonyl alpha-position monomethyl substituted compound. According to the synthesis method of the carbonyl alpha-position monomethyl substituted compound, the target compound can be conveniently obtained, the toxicity of reagents participating in the reaction is small, and the reaction conditions are mild. Post-treatment is simple and safe, the product quality is good, and the method is suitable for large-scale production.
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Paragraph 0026-0029; 0039-0042; 0048-0052
(2022/01/12)
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- Preparation method of ibuprofen impurity B
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The invention provides a preparation method of an ibuprofen impurity B, and belongs to the technical field of preparation of drug impurity standard substances, and the preparation method comprises thefollowing steps: step 1, carrying out coupling reaction on a compound shown in a formula 1 and ethyl bromoacetate under the action of a catalyst and a first alkali to obtain a compound shown in a formula 2; 2, performing substitution reaction on the compound shown in the formula 2 and methyl iodide under the action of second alkali to obtain a compound shown in a formula 3; and 3, hydrolyzing thecompound shown in the formula 3 under the action of a third alkali to obtain the ibuprofen impurity B. The method has the advantages of simplicity in operation, short preparation period, few byproducts, easiness in purification and high yield, the prepared ibuprofen impurity B has high purity and no obvious impurity point, meets the requirements of impurity reference substances, can be used as anibuprofen impurity B standard substance, is applied to qualitative and quantitative research and detection of the ibuprofen impurity B, and has certain significance for quality control of ibuprofen bulk drugs and related preparations thereof.
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- The synthesis of alkylated or acylated nitroarene cyclopentadienyliron complexes: An alternative approach to the synthesis of arylated alkanoates
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Time-dependent oxidation of η6-alkylaniline-η5-cyclopentadienyliron hexafluorophosphates, 17-32, allows for the preparation of nitrobenzene complexes with alkyl 33-48 or keto 49 substituents. Alkylnitroarene complexes are prepared by the oxidation of their corresponding aniline complexes with H2O2 in CF3CO2H for 20 min. An increase in the reaction time to 24 h gives rise to nitroarene complexes with keto substituents in lower yields. The use of nitroarenes as starting materials in the synthesis of alkanoates is of importance since it allows for the preparation of a large number of this class of compounds with a variety of alkyl substituents. Two different approaches have been utilized to allow for the synthesis of alkanoates. The first approach involves nucleophilic aromatic substitution of alkylnitrobenzene complexes with ethyl alkylacetoacetates followed by demetallation to give the alkanoates. This methodology allows for the preparation of these esters with a variety of alkyl substituents in either the meta or para positions. Another route outlines the reaction of phenylsulfonylacetonitrile with nitroarene complexes to prepare alkanoic acid precursors with alkyl substituents in the ortho, meta and para positions. The preparation of a larger pool of nitroarene complexes clearly demonstrates the advantage of using the cyclopentadienyliron arene complexes in the synthesis of alkanoates or their precursors, arylated phenylsulfonylacetonitriles, over traditional synthetic routes.
- Abd-El-Aziz, Alaa S.,Boraie, Waleed,Al-Salem, Najceb,Sadek, Salwa A.,Epp, Karen M.
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p. 1469 - 1479
(2007/10/03)
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