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Nucleophilic Substitution at Nitrogen: Mechanisms and Intermediates

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AN ABSTRACT OF THE THESIS OF PIERRE FRANCOIS BLANCHET for theDOCTOR OF PHILOSOPHY (Name) (Degree) in CHEMISTRY (INORGANIC) presented on c)3)J J73 (Major) Date) Title:NUCLEOPHILIC SUBSTITUTION AT NITROGEN. MECHANISMS AND INTERMEDIATES INVOLVED IN SUBSTITUTION REACTIONS OF THE HYDROXYLAMINE-0- SULFONATE Redacted for privacy Abstract approved: James H. Krueger 0 The kinetics of reactions between various nucleophiles and hydroxylamine-0-sulfonate ion, H2NOSO3, have beenstudied spectrophotometrically in water and in 50 wt % water-methanol. The objective of the study was to make a quantitative evaluation of nucleo- philic reactivity at the trivalent nitrogen center in H2NOS03. show first- Reactions of the various nucleophiles (Nu) with H NOSO3 order behavior in both reactants, leading to the general rate law -d[H2NOS03] /dt = k2[H2NOS03][Nu.z]. From the kinetic studies the following results were obtained: Nucleophile 1<2 AH* A S 1<H"D pH range Ivi- lsec-1 kcal/mole eu (C 2, 0 ± 0.1 7. 4 ± 0, 1 -32±1 1.6± 0. 1 5 - 7 6H 5)3P 0. 069 ± 0, 06 1 1 6 ± 0.3 -24, 4± 1 1.3± 0.1 3 - 8 2- 2203 0. 550 ± 0, 015 10, 8 ± 0, 1 -22,80,5 1, 1 ± 0,05 3 - 9 (HN)C=S 1,63 ± 0, 07 7. 4 ± 0,2 5 1, 1 ± 0, 1 3 -11 2 2 -32, 3±1. For the reactions of (CH 5)3P, (H2N)2C =S, and I, the second-order 6 rate constants decrease below pH 3 and, in the case of Nu = I, it was possible to obtain the rate constant for reaction with molecular -1 H3NOSO3, . kHOS 0.023 M sec A general mechanism is proposed in which the nucleophile attacks the nitrogen atom of H2NOSO3in a typical SN2 process. z z+1 2- Nu+ HNOS03 > Nu- - > NuNH + SO4 2 H \H 2 The mechanism is strongly supported by identification of an z+1 NuNH species, either as an intermediate, or as the product in 2 each of the reactions, except that involving iodide.Deuterium isotope effect studies, steric effects, and the observed pH dependence strongly suggest that nitrogen attack takes place in the iodide reaction as well. The three NuNHz+1species detected are the well-known 2 (CH )PNH ion, the previously reported HNSSO ion, and the 6 53 2 2 3 +' novel cation, (HN)CSNH isolated as the sulfate salt.Infra-red 2 2 2 spectra of the latter two are reported and the properties and several reactions of (HN)CSNH 2+ are described. 2 2 From the results, the trivalent nitrogen atom in hydroxyl- amine-O-sulfonate ion is characterized as a fairly soft acid center in terms of the hard and soft acid and base (HSAB) principle.Polariz- ability and ease of oxidation of the nucleophile clearly are more important than proton basicity in determining reactivity of the nucleophile. Attempts to study the reactions of N-methyl and N-benzoyl substituted hydroxylamine -0-sulfonate with the same nucleophiles are reported.Because the reactions are very slow, only qualitative results are reported. Nucleophilic Substitution at Nitrogen.Mechanisms and Intermediates Involved in Substitution Reactions of the Hydroxylamine-O-sulfonate Ion by Pierre Francois Blanchet A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed May 1973 Commencement June 1974 APPROVED: Redacted for privacy Associ irofesso.r 'of ChemisOy in charge of major Redacted for privacy Chairman of Department of Chemistry Redacted for privacy Dean of Graduate School Date thesis is presented .2/ 1q13 Typed by Clover Redfern for ierre Francois Blanchet A HelAne et I. Sophia. ACKNOWLEDGMENTS My deepest gratitude goes to my wife for her patience, love and understanding during the last four years.I have been fortunate enough to work under the direction of an excellent chemist and a wonderful human being, Dr. James Krueger.I wish to thank him for his guid- ance, interest and patience, especially in writing this thesis. Encouragement and helpful discussions by my fellow graduate students, especially members of my research group, are acknowledged with thanks.Many thanks to David Benson for proofreading my thesis. Finally I wish to thank all the people who made our stay in Oregon so enjoyable. TABLE OF CONTENTS Chapter Page I.INTRODUCTION 1 Synthesis and Properties of Hydroxylamine-0- sulfonic Acid 1 Syntheses Involving Hydroxylamine sulfonic Acid 3 Previous Kinetic Studies 5 Purpose of the Work 7 HSAB Pr inciple 9 II,EXPERIMENTAL 11 Reagents 11 Solvents 15 Instrumentation and Temperature Control 16 Temperature Calibration 17 Typical Kinetic Run 17 Intermediates and Products 19 Preparation of Potassium Thiohydroxylamine-S- sulfonate 19 Preparation of S-aminoisothiouronium Sulfate 20 Preparation of Formamidinedisulfide Dichloride Instrumentation Used 23 III.RESULTS 24 Tr iphenylpho s phine -hydroxylamine sulfonate Reaction 24 Determination of the Rate Law 24 Stoichiometry 26 Temperature Effect 28 Deuterium Isotope Effect 30 Reaction with Added Formaldehyde 32 Runs at Lower pH 34 Potassium Iodide -hydroxylamine - sulfonate Ion Reaction 34 Determination of the Rate Law 37 Stoichiometry 41 Determination of the Stoichiometry by Titration41 Spectrophotometric Determination of the Stoichiometry 43 Temperature Effect 44 Deuterium Isotope Effect 46 Solvent Effect 46 Reactions with Added Chloride and Bromide 48 Chapter Page Potassium Thiosulfate -hydroxylamine -0 -sulfonate Ion Reaction 49 Determination of the Rate Law 51 Stoichiometry 53 Temperature Effect 56 Deuterium Isotope Effect 59 Hydrogen-Ion Dependence of the Thiohydroxyl- amine -S -sulfonate - thiosulfate Reaction 59 Determination of the pKA of Thiohydroxylamine- S-sulfonic Acid 63 Ion-Pair Effects in the Reaction of Hydroxylamine- 0-sulfonate to Form Tetrathionate 64 Reactions at Lower pH 67 Thiourea -hydroxylamine -0 - sulfonic Acid Reaction 69 Determination of the Rate Law 72 Stoichiometry 72 Temperature Effect 78 Deuterium Isotope Effect 81 Solvent Effect 81 Reactions at Lower pH 81 Second-Order Reaction with Thiourea in Excess 82 Nucleophilic Reactions Involving Substituted Hydroxylamine-O-sulfonate Ion 84 Determination of the Rate Law 85 Determination of the Rate Constants 87 IV.DISCUSSION 89 General Mechanism 89 Site of Attack 91 Deuterium Isotope Effects 92 Specific Mechanisms 93 T riphenylpho s ph ine 93 Iodide 94 Thiosulfate 97 Thiourea 103 Reactions Involving Substituted Hydroxylamine-0- sulfonate Ion 106 Relative Reactivity of the Nucleophiles 108 BIBLIOGRAPHY 111 APPENDICES 115 Appendix I 115 Appendix II 119 LIST OF TABLES Table Page 1.Kinetic data for the triphenlyphosphine-hydroxylamine- 0-sulfonate ion reaction at p. = 0.075 M and 20. 34° in 50 wt % methanol-water solvent. 27 2.Temperature dependence of the triphenylphosphine hydroxylamine -O- sulfonate ion atµ = 0.075 M and pH 5.75. 29 3.Kinetic data for the iodide -hydroxylamine -0-sulfonate ion reaction at H. = 0, 1 M and 20.34° in water. 35 4.Kinetic data for the iodide -hydroxylamine-O-sulfonate ion reaction atµ = 0. 1 M at 20.34° and at pH lower than 3 in water. 36 5.Temperature dependence of the iodide-hydroxylamine-0- sulfonate ion reaction at p. = 0.1 M and at pH 4.75. 45 6.Kinetic data for the thiosulfate-hydroxylax-nine-0- sulfonate ion reaction at p. -70.1 Mat 20.34° and in water. 50 7.Temperature dependence of the thiosulfate-hydroxylarnine- 0-sulfonate ion reaction at p. = 0.1 M and at pH 4.75 in water. 57 8.Kinetic data for the thiosulfate-thiohydroxylamine-S- sulfonate reaction at p. = 0.1 M and at 20. 34° in water. 61 9.Kinetic data for the ion-pairing effect in the thiosulfate- hydroxylamine -O- sulfonate ion reaction atµ = 0.1 M at 20.34° and at pH 4.75 in water. 65 10.Kinetic data for the thiourea-hydroxylamine-O-sulfonate ion reaction at p. = 0.1 M at 20.34° and at different pH values in water. 70 11.Temperature dependence of the thioure-hydroxylamine- 0-sulfonate ion reaction at p. = 0.1 M and at pH 4.75 in water. 79 Table P, au. 12.Kinetic data for the thiour ea -hydroxylamine-0- sulfonate ion reaction at N. = 0. 1 M at 20.34° and at pH lower than 3.0 in water. 83 13.Kinetic data for the reactions involving N-methyl- hydroxylamine -0-sulfonate with triphenylphosphine and thiourea. 86 14.Nucleophilic reactivity toward hydroxylamine-0- sulfonate ion in H2O at 20. 4°. 110 LIST OF FIGURES Figure Page 1.Pseudo-first-order plots for the triphenylphosphine- hydroxylamine-0-sulfonate ion reaction at p. = 0.075 M at 20. 34° and at pH 5.75 in 50 wt % methanol-water solvent. 25 2.Temperature dependence on the second-order rate constant for the triphenylphosphine-hydroxylamine- 0-sulfonate ion reaction, 31 3.Second-order rate constant versus p1-1 for the iodide- hydroxylamine-O-sulfonate ion reaction at 20.34° and p. = 0.1 M. 38 Pseudo-first-order plots for the iodide-hydroxylamine - 0-sulfonate ion reaction at p. = 0.1 M, at 20. 34° and pH 4.75 in water. 39 5.Temperature dependence of the second-order rate constant for the iodide-hydroxylamine-O-sulfonate ion reaction. 47 6.Second-order plots for the thiosulfate -hydroxylamine 0-sulfonate ion reaction at p. = 0.1 M at 20. 34° and at pH 4.75 in water. 52 7.Uv spectrum of potassium thiohydroxylamine-S-sulfonate in water. 54 8.Temperature dependence of the second-order rate constant for the thiosulfate-hydroxylamine-O-sulfonate ion reaction. 58 9.k2(obs) for the thiosulfate-thiohydroxylamine-S- sulfonate reaction as a function of H+ concentration. 62 10.Plot to determine the ion-pairing effect on the thiosulfate hydroxylamine-sulfonate ion reaction at p.
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  • Preparation from Hydroxylammonium Sulfate of Alcoholic Hydroxylamine

    Preparation from Hydroxylammonium Sulfate of Alcoholic Hydroxylamine

    ratentamt JcuropaiscnesEuropean Patent Office ® Publication number: 0108 294 vsrriceOffice europeeneuroDeen aesdes Drevetsbrevets B1 ® EUROPEAN PATENT SPECIFICATION (45) Date of publication of patent specification: 06.02.91 (g) int. CI.5: C 01 B 21/14, C 07 C 51/41, C 07 C 249/04< C 07 C 259/04 ® Application number: 83110342.9 (22) Date of filing: 17.10.83 w> preparation trom nyaroxyiammomum suirate ot alcoholic hydroxylamine solutions and of oximes, hydroxamic acids and other hydroxylammonium salts via alcoholic hydroxylamine solutions. & rriorixy: ui.il.tsz US 437920 (73) Proprietor: ALLIED-SIGNAL INC. (a Delaware 23.09.83 US 534292 corporation) 23.09.83 US 534291 Columbia Road and Park Avenue P.O. Box 2245R Morristown New Jersey 07960 (US) g) Date of publication of application: 16.05.84 Bulletin 84/20 ® I nventor: Mathew, Chempolil Thomas 9 Openaki Road tandolph New Jersey 07869 (US) ruDiication ot the grant of the patent: nventor: Ulmer, Harry Edwards 06.02.91 Bulletin 91/06 !6 Ellsworth Avenue /lorristown. New Jersey 07960 (US) HJ Designated Contracting States: BE CH DE FR GB IT LI NL SE J5) Representative: Brock, Peter William et al URQUHART-DYKES & LORD 91 Wimpole Street London W1M8AH (GB) nererences citea: DE-B-1247284 JS-A-2483252 JS-A-3420 621 JOURNAL OF ORGANIC CHEMISTRY, vol. H,May 1946, pages 207-214, Washington, US; ID. HURD et al.: "Hydroxamic acids from iliphatic dicarboxylic acids" wie. vviuiim nine monms rrom Tne puDiication or the mention of the grant of the European patent, any person may jive notice to the European Patent Office of opposition to the European patent granted.