A Simple and Efficient Green Method for the Deprotection of N-Boc in Various Structurally Diverse Amines under Water-mediated Catalyst-free Conditions

Cheraiet, Zinelaabidine; Ouarna, Souad; Zoubir, Jamel; Berredjem, Malika; Aouf, Nour-Eddine

doi:10.5539/ijc.v4n3p73

Cited by 31 publications

(29 citation statements)

References 26 publications

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“…In general, the t -Boc group can be removed by treatment with a strong acid, such as trifluoroacetic acid, to give the original compound in high yield [ 8 ]. Deprotection can also be efficiently achieved by dissolution in distilled water at 100 °C within several tens of minutes, without using a strong acid [ 9 ]. In particular, seizures of t -Boc-protected MDMA and MP, phenethylamines containing secondary amino groups, have been reported.…”

Section: Introductionmentioning

confidence: 99%

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

et al. 2018

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PurposePhenethylamines constitute the majority of drug-related arrests in Japan. Recently, the smuggling of tert-butoxycarbonyl (t-Boc)-protected phenethylamines has become of increasing concern, because of the difficult identification of these masked substances.MethodsIn this study, a rapid and accurate method for the detection of t-Boc-methamphetamine (t-Boc-MP) by direct analysis in real time–time-of-flight-mass spectrometry (DART–TOF-MS) was developed. The efficiency of the method was evaluated by comparison with conventional gas chromatography–MS (GC–MS) and liquid chromatography–TOF-MS (LC–TOF-MS) techniques.ResultsDuring GC–MS analysis of t-Boc-MP, MP was generated in the injection port, which can lead to an analytical error. In the LC–TOF-MS spectrum, fragment ions were detected, which were generated by McLafferty rearrangement in the ion source. On the other hand, in the DART–TOF-MS analysis of t-Boc-MP, pyrolysis could be suppressed by using a micro-syringe injection method, and the fragment ions generated by McLafferty rearrangement were still observed. Moreover, protonated t-Boc-MP could be detected.ConclusionsHence, DART–TOF-MS provides a rapid and accurate method for the detection of t-Boc-MP, allowing suppression of the pyrolysis reaction and identification of both fragment ions and protonated t-Boc-MP. To our knowledge, this is the first report for detecting t-Boc-MP by MS techniques.

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Section: Introductionmentioning

confidence: 99%

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

et al. 2018

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“…For example, melting point tests of 2 showed a broad melting point around 80°C to 89°C, followed by generation of bubbles in the open capillary tube at temperatures between 110°C and 120°C. We hypothesize that the bubbles were caused by generation of CO 2 during thermolysis of the N,N′,N′′,N′′ ‐ tetrakis ‐Boc groups between 110°C and 120°C …”

Section: Resultsmentioning

confidence: 99%

Improved synthesis of 4‐[¹⁸F]fluoro‐m‐hydroxyphenethylguanidine using an iodonium ylide precursor

Jung

Raffel

2019

Labelled Comp Radiopharmac

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Fluorine-18 labeled hydroxyphenethylguanidines were recently developed in our laboratory as a new class of PET radiopharmaceuticals for quantifying regional cardiac sympathetic nerve density in heart disease patients. Studies of 4-[ 18 F]fluoro-m-hydroxyphenethylguanidine ([ 18 F]4F-MHPG) and 3-[ 18 F] fluoro-p-hydroxyphenethylguanidine ([ 18 F]3F-PHPG) in human subjects haveshown that these radiotracers can be used to generate high-resolution maps of regional sympathetic nerve density using the Patlak graphical method. Previously, these compounds were synthesized using iodonium salt precursors, which provided sufficient radiochemical yields for on-site clinical PET studies. However, we were interested in exploring new methods that could offer significantly higher radiochemical yields. Spirocyclic iodonium ylide precursors have recently been established as an attractive new approach to radiofluorination of electron-rich aromatic compounds, offering several advantages over iodonium salt precursors. The goal of this study was to prepare a spirocyclic iodonium ylide precursor for synthesizing [ 18 F]4F-MHPG and evaluate its efficacy in production of this radiopharmaceutical. Under optimized automated reaction conditions, the iodonium ylide precursor provided radiochemical yields averaging 7.8% ± 1.4% (n = 8, EOS, not decay corrected), around threefold higher than those achieved previously using an iodonium salt precursor. With further optimization and scale-up, this approach could potentially support commercial distribution of [ 18 F]4F-MHPG to PET centers without on-site radiochemistry facilities.

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“…In the course of our studies on PMONPs, we were interested in nanomaterials possessing the tert-butoxycarbonyl (BOC) group. Indeed, BOC, as an amine protective group, can be quickly removed in water at 90-100 °C, generating CO2 [29,30]. As HIFU can heat up to 70-80 °C [31,32], we thought of synthesizing PMONPs from polytrialkoxysilylated BOCfunctionalized molecules in order to develop PMONP-based contrast agents for HIFU.…”

Section: Introductionmentioning

confidence: 99%

Periodic Mesoporous Organosilica Nanoparticles with BOC Group, towards HIFU Responsive Agents

Li¹,

Gascó

Delalande

et al. 2020

Molecules

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Periodic Mesoporous Organosilica Nanoparticles (PMONPs) are nanoparticles of high interest for nanomedicine applications. These nanoparticles are not composed of silica (SiO2). They belong to hybrid organic–inorganic systems. We considered using these nanoparticles for CO2 release as a contrast agent for High Intensity Focused Ultrasounds (HIFU). Three molecules (P1–P3) possessing two to four triethoxysilyl groups were synthesized through click chemistry. These molecules possess a tert-butoxycarbonyl (BOC) group whose cleavage in water at 90–100 °C releases CO2. Bis(triethoxysilyl)ethylene E was mixed with the molecules Pn (or not for P3) at a proportion of 90/10 to 75/25, and the polymerization triggered by the sol-gel procedure led to PMONPs. PMONPs were characterized by different techniques, and nanorods of 200–300 nm were obtained. These nanorods were porous at a proportion of 90/10, but non-porous at 75/25. Alternatively, molecules P3 alone led to mesoporous nanoparticles of 100 nm diameter. The BOC group was stable, but it was cleaved at pH 1 in boiling water. Molecules possessing a BOC group were successfully used for the preparation of nanoparticles for CO2 release. The BOC group was stable and we did not observe release of CO2 under HIFU at lysosomal pH of 5.5. The pH needed to be adjusted to 1 in boiling water to cleave the BOC group. Nevertheless, the concept is interesting for HIFU theranostic agents.

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A Simple and Efficient Green Method for the Deprotection of N-Boc in Various Structurally Diverse Amines under Water-mediated Catalyst-free Conditions

Cited by 31 publications

References 26 publications

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

Improved synthesis of 4‐[¹⁸F]fluoro‐m‐hydroxyphenethylguanidine using an iodonium ylide precursor

Periodic Mesoporous Organosilica Nanoparticles with BOC Group, towards HIFU Responsive Agents

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A Simple and Efficient Green Method for the Deprotection of N-Boc in Various Structurally Diverse Amines under Water-mediated Catalyst-free Conditions

Cited by 31 publications

References 26 publications

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

Rapid detection of tert-butoxycarbonyl-methamphetamine by direct analysis in real time time-of-flight mass spectrometry

Improved synthesis of 4‐[18F]fluoro‐m‐hydroxyphenethylguanidine using an iodonium ylide precursor

Periodic Mesoporous Organosilica Nanoparticles with BOC Group, towards HIFU Responsive Agents

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Improved synthesis of 4‐[¹⁸F]fluoro‐m‐hydroxyphenethylguanidine using an iodonium ylide precursor