4 dimethylaminopyridine

      4-Dimethylaminopyridine GudangMovies21 Rebahinxxi LK21

      4-Dimethylaminopyridine (DMAP) is a derivative of pyridine with the chemical formula (CH3)2NC5H4N. This white solid is of interest because it is more basic than pyridine, owing to the resonance stabilisation from the NMe2 substituent.
      Because of its basicity, DMAP is a useful nucleophilic catalyst for a variety of reactions such as esterifications with anhydrides, the Baylis-Hillman reaction, hydrosilylations, tritylation, the Steglich rearrangement, Staudinger synthesis of β-lactams and many more. Chiral DMAP analogues are used in kinetic resolution experiments of mainly secondary alcohols and Evans auxiliary type amides.


      Preparation


      DMAP can be prepared in a two-step procedure from pyridine, which is first oxidized to 4-pyridylpyridinium cation. This cation then reacts with dimethylamine:


      Esterification catalyst



      In the case of esterification with acetic anhydrides the currently accepted mechanism involves three steps. First, DMAP and acetic anhydride react in a pre-equilibrium reaction to form an ion pair of acetate and the acetylpyridinium ion. In the second step the alcohol adds to the acetylpyridinium, and elimination of pyridine forms an ester. Here the acetate acts as a base to remove the proton from the alcohol as it nucleophilically adds to the activated acylpyridinium. The bond from the acetyl group to the catalyst gets cleaved to generate the catalyst and the ester. The described bond formation and breaking process runs synchronous concerted without the appearance of a tetrahedral intermediate. The acetic acid formed will then protonate the DMAP. In the last step of the catalytic cycle the auxiliary base (usually triethylamine or pyridine) deprotonates the protonated DMAP, reforming the catalyst. The reaction runs through the described nucleophilic reaction pathway irrespective of the anhydride used, but the mechanism changes with the pKa value of the alcohol used. For example, the reaction runs through a base-catalyzed reaction pathway in the case of a phenol. In this case, DMAP acts as a base and deprotonates the phenol, and the resulting phenolate ion adds to the anhydride.


      Safety


      DMAP has a relatively high toxicity and is particularly dangerous because of its ability to be absorbed through the skin. It is also corrosive.


      Related compound


      4-Pyrrolidinylpyridine


      References




      Further reading


      B. Neises; W. Steglich (1990). "Esterification of Carboxylic Acids with Dicyclohexylcarbodiimide/4-Dimethylaminopyridine: tert-Butyl Ethyl Fumarate". Organic Syntheses; Collected Volumes, vol. 7, p. 93.
      I. Held; P. von den Hoff; D. S. Stephenson; H. Zipse (2008). "Domino Catalysis in the Direct Conversion of Carboxylic Acids to Esters". Adv. Synth. Catal. 11/12 (11–12): 1891–1900. doi:10.1002/adsc.200800268.

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    4 dimethylaminopyridine

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    4-Dimethylaminopyridine - Wikipedia

    4-Dimethylaminopyridine (DMAP) is a derivative of pyridine with the chemical formula (CH 3) 2 NC 5 H 4 N. This white solid is of interest because it is more basic than pyridine, owing to the resonance stabilisation from the NMe 2 substituent.

    4-Dimethylaminopyridine | C7H10N2 | CID 14284 - PubChem

    4-Dimethylaminopyridine | C7H10N2 | CID 14284 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

    4- (Dimethylamino)pyridine ReagentPlus , = 99 1122-58-3

    4-(Dimethylamino)pyridine (DMAP) is a highly versatile nucleophilic catalyst for acylation reactions and esterifications. It is also employed in various organic transformations like Baylis-Hillman reaction, Dakin-West reaction, protection of amines, C-acylations, silylations, applications in natural products chemistry, and many others.

    4-Dimethylaminopyridine | 1122-58-3 - ChemicalBook

    Jan 27, 2025 · 4-Dimethylaminopyridine (CAS 1122-58-3) information, including chemical properties, structure, melting point, boiling point, density, formula, molecular weight, uses, prices, suppliers, SDS and more, available at Chemicalbook.

    4-(Dimethylamino)pyridine, 99%, Thermo Scientific Chemicals

    4-(Dimethylamino)pyridine is a useful nucleophilic catalyst for various reactions viz. esterifications with anhydrides, the Baylis-Hillman reaction, hydrosilylations, tritylation and Steglich rearrangement.

    4-(Dimethylamino)pyridine ≥99% | Sigma-Aldrich - MilliporeSigma

    Four sulfated derivatives (RHPS) with variable degrees of substitution (DS) were obtained by the chlorosulfonic acid method with ionic liquids (ILs) as solvent and 4-dimethylaminopyridine (DMAP) as catalyst.

    DMAP 4- (Dimethylamino)pyridine Novabiochem 1122-58-3

    DMAP 4-(Dimethylamino)pyridine Novabiochem®; CAS Number: 1122-58-3; Synonyms: DMAP,4-Dimethylaminopyridine at Sigma-Aldrich

    SAFETY DATA SHEET - Fisher Sci

    4-Dimethylaminopyridine Revision Date 24-Dec-2021 General Advice Show this safety data sheet to the doctor in attendance. Immediate medical attention is required. Eye Contact In the case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Rinse immediately with plenty of water, also under the eyelids, for at ...

    4-dimethylaminopyridine DMAP | C14H20N4 | CID 23202903

    4-dimethylaminopyridine DMAP | C14H20N4 | CID 23202903 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

    4-(Dimethylamino)pyridine CAS 1122-58-3 | 820499 - Merck

    4-(Dimethylamino)pyridine for synthesis. CAS 1122-58-3, pH 11 (60 g/l, H₂O, 20 °C). - Find MSDS or SDS, a COA, data sheets and more information.