Acidic and basic amide hydrolysis

O’Connor, Charmian J.

doi:10.1039/qr9702400553

Cited by 99 publications

(67 citation statements)

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“…The deamidation products, RPR 108969 and RPR 108970, likely result from straightforward acidcatalyzed hydrolysis of the free amides. 7 The increase in rate of formation of these products with decreasing pH supports this mechanism. Of the five free amides present in sCT, only the Gln amides undergo acid-catalyzed hydrolysis to any significant extent.…”

Section: Discussionmentioning

confidence: 74%

Degradation Pathways of Salmon Calcitonin in Aqueous Solution

Windisch¹,

DeLuccia²,

Duhau³

et al. 1997

Journal of Pharmaceutical Sciences

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Salmon calcitonin (sCT), a 32-amino-acid peptide, is the active component in many pharmaceuticals used for the management of bone diseases. The degradation pathways of sCT were determined, and the structures of the major degradation products were identified. Aqueous solutions of sCT at pH values of 3, 4, 5, and 6 were degraded, and the major degradation products were detected using reversed phase and size-exclusion high-performance liquid chromatography (HPLC). The degradation rate and pathways of sCT are strongly dependent on pH in the pH range between 3 and 6. The major degradation products were isolated by semipreparative HPLC and identified using a variety of spectroscopic and bioanalytical techniques. The results show that sCT can undergo hydrolyses resulting in cleavage of the 1-2 amide bond and deamidation of the Gln14 and Gln20 residues, sulfide exchange that leads to an unusual trisulfide derivative, and dimerization to reducible and nonreducible dimers. The mechanisms for the pathways can be rationalized from known degradation pathways of peptide and proteins.

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Section: Discussionmentioning

confidence: 74%

Degradation Pathways of Salmon Calcitonin in Aqueous Solution

Windisch¹,

DeLuccia²,

Duhau³

et al. 1997

Journal of Pharmaceutical Sciences

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“…30,31 Therefore, to check the feasibility of the intermediate amidium cation to crystallize with PbI 3 − we select urea and ternary amides, as shown in Figure 2. Although urea does not experience steric hindrance, it also has a low hydrolysis rate due to the relative stability of the protonated state.…”

Section: Amidesmentioning

confidence: 99%

Amide-Templated Iodoplumbates: Extending Lead-Iodide Based Hybrid Semiconductors

Eppel

Fridman

Frey

2015

Crystal Growth & Design

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Lead iodide−organic hybrids (iodoplumbates) have emerged as a class of materials with promising electronic and optical properties, and potential applications in photovoltaics and electronic devices. Hybrid iodoplumbates are composed of organic cations and lead iodide anions that exhibit diverse morphologies which determine the optical and electronic properties of the crystal. However, the diversity of the iodoplumbates is limited by the types of organic cations amenable for integration into the structure. Amides represent one of the largest groups of organic molecules, yet no examples of iodoplumbates based on protonated amide cations have been demonstrated so far. In this work, we show that it is possible to consistently grow iodoplumbates from amides following two distinct pathways. The first pathway involves growing iodoplumbates using amidium (protonated amides) as the organic cation in the crystal, which occurs for tertiary amides and urea. The second pathway involves growing iodoplumbates from primary and secondary amides, resulting in crystals containing the ammonium hydrolysis product of the amide. This path also leads to an interesting case of ring opening crystallization. The lead iodide one-dimensional chain motif composes most of the resulting structures. The large number of available amide molecules suggests that this method considerably expands the range of possible iodoplumbate structures. ■ INTRODUCTIONLead(II) iodide−organic hybrid materials (iodoplumbates) have been extensively explored owing to their diverse range of structural motifs which induce a variety of optical and electronic properties. Iodoplumbate optical properties include photoluminescence, 1,2 photochromic, 3,4 and nonlinear optics, 5−9 while the electronic features include semiconductivity 4,5,10−12 and dielectric 13 behaviors. These properties make iodoplumbate materials promising candidates for various applications including solar cell, 14−16 light emitting diodes, 17 and dielectric media. 13 The optical and electrical properties of iodoplumbates are mainly determined by the topology of the inorganic lead(II) iodide component. 12 The overall crystal structure of iodoplumbates is determined by the interplay between the negatively charged lead(II) iodide octahedral complex and the positively charged organic cations. 4,12 The geometry and topology of the lead(II) iodide component are, therefore, controlled by the type of organic cation used to form the crystals. Namely, the organic cation acts as a template, which controls the topology, dimensionality, and geometry of the inorganic lead-iodide complex and by this controls the optical and electronic properties of these materials. It is, therefore, possible to control and tune the material properties by changing the type of organic cations used for the crystallization. 4,12 It has been demonstrated that depending on the type of organic cation, the topology of the lead(II) iodide complex can obtain a range of structural motifs with various dimensionalities including one-dimensional (1...

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“…Hydrolysis of an amide, a nitrile or an ester functional group is a very common transformation in organic synthesis with many applications and a common way to prepare carboxylic acids. In general, nitriles and amides are exceptionally stable to acid and basic hydrolysis and classically they are hydrolyzed under vigorous reaction conditions and long reaction times [1][2][3] by heating in the presence of mineral acids or concentrated solutions of alkali hydroxides (10-40%), which can sometimes cause undesirable side reactions and low yield.…”

Section: Introductionmentioning

confidence: 99%

A mild alkaline hydrolysis of N- and N,N-substituted amides and nitriles

Théodorou¹,

Paraskevopoulos²,

Skobridis³

2015

Arkivoc

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A mild protocol for the alkaline hydrolysis of secondary and tertiary amides in non-aqueous conditions, by the use of NaOH in methanol/dichloromethane or methanol/dioxane (1:9) at room temperature or under reflux, has been developed and a plausible reaction mechanism is discussed. Primary amides are hydrolyzed much slower than with the classical procedure, while nitriles are converted selectively to primary amides.

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Acidic and basic amide hydrolysis

Cited by 99 publications

References 0 publications

Degradation Pathways of Salmon Calcitonin in Aqueous Solution

Degradation Pathways of Salmon Calcitonin in Aqueous Solution

Amide-Templated Iodoplumbates: Extending Lead-Iodide Based Hybrid Semiconductors

A mild alkaline hydrolysis of N- and N,N-substituted amides and nitriles

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