ChemInform Abstract: Selective Monoalkylation of Amines.

Croce, Piero Dalla; Rosa, Concetta La; Ritieni, Alberto

doi:10.1002/chin.198911109

Cited by 6 publications

(14 citation statements)

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“…As Bocderivatives of primary amines have previously been selectively alkylated, two different alkyl substituents can in principle be introduced stepwise into Boc 2 NH when used instead of phthalimide. 33 Boc 2 N-compounds were originally prepared from urethanes with Boc 2 O/DMAP. 13 For amine synthesis from halides alkylation of Boc 2 NH is rather convenient.…”

Section: Boc 2 -Amine Derivatives [R-n(boc) 2 ] 29mentioning

confidence: 99%

Dual protection of amino functions involving Boc

Ragnarsson

Grehn

2013

RSC Adv.

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Protecting groups play a pivotal role in the synthesis of multifunctional targets and as amino functions often occur in this context, issues related to their protection become prominent. Primary amines are unique because they can accommodate two such groups. This review highlights various aspects related to the synthesis, properties and applications of products containing one or two Boc-groups resulting from dual protection of amines and amides. Attention is directed towards cases of facilitated cleavage due to mutual interaction between two protecting groups on the same nitrogen.a GH any group. b G any group except hydrogen.

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Section: Boc 2 -Amine Derivatives [R-n(boc) 2 ] 29mentioning

confidence: 99%

Dual protection of amino functions involving Boc

Ragnarsson

Grehn

2013

RSC Adv.

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“…To optimize process efficiency, a study was undertaken to introduce the halopropyl group in a single step using a 1,3-dihalopropane. Selective monoalkylation of primary amines has been a long-standing and fundamental challenge in organic synthesis . Several approaches to this problem are reported in the literature including base-promoted alkylation (with , and without partial N -protection, reductive amination, and reductive alkylations .…”

Section: Resultsmentioning

confidence: 99%

“…Selective monoalkylation of primary amines has been a long-standing and fundamental challenge in organic synthesis . Several approaches to this problem are reported in the literature including base-promoted alkylation (with , and without partial N -protection, reductive amination, and reductive alkylations . Most of these, by virtue of the reaction conditions, would preclude the direct introduction of a halopropyl moiety.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of (R)-Boc-2-methylproline via a Memory of Chirality Cyclization. Application to the Synthesis of Veliparib, a Poly(ADP-ribose) Polymerase Inhibitor

et al. 2019

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(R)-Boc-2-methylproline (3a) was synthesized in good yield with excellent stereochemical control from alanine benzyl ester hydrochloride 11. The process, which is based on a modification of one described by Kawabata, proceeds in four steps and requires no chromatography. The product (R)-Boc-2-methylproline (3a) was then carried forward in three steps to produce veliparib 1, a poly(ADP-ribose) polymerase inhibitor.

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“…The phenolic moiety was protected as the methoxyethoxymethyl (MEM) ether 23 to give 2. Reduction of the nitro group 7 with NaBH 4 in ethanol lead to aniline 3, which was protected with a Boc group under standard conditions 24,25 to give compound 4 (Scheme 1), in order to prevent dialkylation in the labelling step. Compound 4 is the key intermediate for the synthesis of cold reference material and for the radiosynthesis of [ 18 F]FBTA.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of a [¹⁸F]fluorobenzothiazole as potential amyloid imaging agent

Berndt

Stanetty

Wanek

et al. 2008

Labelled Comp Radiopharmac

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This study describes the synthesis of a fluoroethylated derivative of [N‐methyl‐11C]2‐(4′‐methylaminophenyl)‐6‐hydroxybenzothiazole ([11C]6‐OH‐BTA‐1; Pittsburgh Compound B (PIB)), an already established amyloid imaging agent. The [11C]methylamino group of [11C]6‐OH‐BTA‐1 was formally replaced by a fluoroethyl group in a cold synthesis via N‐alkylation of N‐Boc‐2‐(4′‐aminophenyl)‐6‐(methoxyethoxymethoxy)benzothiazole with fluoroethyl tosylate. Subsequent deprotection gave the target compound 2‐[4′‐(2‐fluoroethyl)aminophenyl]‐6‐hydroxybenzothiazole (FBTA). In a radioligand competition assay on aggregated synthetic amyloid fibrils using N‐[3H‐methyl]6‐OH‐BTA‐1, 100 nM FBTA inhibited binding with 93 ± 1 and 83 ± 1% efficiency for Aβ1–40 and Aβ1–42, respectively. For the radiosynthesis a precursor carrying a tosylethyl moiety was prepared allowing the introduction of [18F]fluoride via nucleophilic substitution with [18F]tetra‐n‐butyl‐ammonium fluoride (TBAF). Subsequent removal of all protecting groups was performed in a one‐pot procedure followed by semi‐preparative HPLC, delivering the target compound [18F]FBTA in good radiochemical yield of 21% on average and radiochemical purity of ⩾98% at EOS. In vitro autoradiography on human postmortem AD brain tissue slices showed intense cortical binding of [18F]FBTA (1 nM), which was displaced in presence of 6‐OH‐BTA‐1 (1 µM). Brain up‐take was evaluated in wild‐type (wt) mice with microPET imaging. Based on these results, [18F]FBTA appears to be a suitable candidate tracer for amyloid imaging in humans. Copyright © 2008 John Wiley & Sons, Ltd.

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ChemInform Abstract: Selective Monoalkylation of Amines.

Abstract: ChemInform Abstract The selective synthesis of the secondary amines (V) is achieved either with isolation of the Boc-derivatives (III) (→ (Va)) or in a one-pot procedure (→ (Vb)) starting from (I).

Cited by 6 publications

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Dual protection of amino functions involving Boc

Dual protection of amino functions involving Boc

Synthesis of (R)-Boc-2-methylproline via a Memory of Chirality Cyclization. Application to the Synthesis of Veliparib, a Poly(ADP-ribose) Polymerase Inhibitor

Synthesis of a [¹⁸F]fluorobenzothiazole as potential amyloid imaging agent

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ChemInform Abstract: Selective Monoalkylation of Amines.

Abstract: ChemInform Abstract The selective synthesis of the secondary amines (V) is achieved either with isolation of the Boc-derivatives (III) (→ (Va)) or in a one-pot procedure (→ (Vb)) starting from (I).

Cited by 6 publications

References 0 publications

Dual protection of amino functions involving Boc

Dual protection of amino functions involving Boc

Synthesis of (R)-Boc-2-methylproline via a Memory of Chirality Cyclization. Application to the Synthesis of Veliparib, a Poly(ADP-ribose) Polymerase Inhibitor

Synthesis of a [18F]fluorobenzothiazole as potential amyloid imaging agent

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Synthesis of a [¹⁸F]fluorobenzothiazole as potential amyloid imaging agent