N-Sulphonylimino Esters

Love, Bernard; Kormendy, Minerva F.

doi:10.1139/v64-028

Cited by 11 publications

(7 citation statements)

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“…The most general approach for the preparation of N -sulfonylimidates consists in the formation of a Pinner salt from a nitrile followed by N -tosylation . A few examples have been described for the direct conversion of triethylorthoacetate into sulfonylimidates, using a large excess of orthoester . The unique method for the preparation of N -sulfinylimidates is the condensation of a sulfinamide with an orthoester under strong acidic catalysis for 3 h at 100 °C .…”

Section: Resultsmentioning

confidence: 99%

“…39 A few examples have been described for the direct conversion of triethylorthoacetate into sulfonylimidates, using a large excess of orthoester. 40 The unique method for the preparation of Nsulfinylimidates is the condensation of a sulfinamide with an orthoester under strong acidic catalysis for 3 h at 100 °C. 41 We wondered, by analogy with the activation of acetals, whether the thermal activation of orthoesters under microwave irradiation would be possible, without any catalyst, and would therefore lead to simpler reaction conditions for the synthesis of Nsulfonylimidates and N-sulfinylimidates.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Metal Free, Microwave Assisted Preparation of N-Sulfonyl and N-Sulfinyl Imines and Imidates

Verrier

Carret

Poisson

2018

ACS Sustainable Chem. Eng.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Metal Free, Microwave Assisted Preparation of N-Sulfonyl and N-Sulfinyl Imines and Imidates

Verrier

Carret

Poisson

2018

ACS Sustainable Chem. Eng.

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“…Compounds with either a carboxyl (1), sulfonate (18), or tetrazole (40) moiety were agonists, while those having a phosphonate (6) or phosphinate (41) moiety were antag- (103) Slaughter, . M.; Miller, R. F. J. Neurosci.…”

Section: Ap4 Receptormentioning

confidence: 99%

“…These studies and in particular the studies that have utilized various agonists and antagonists of excitatory neurotransmission have indicated that at least four receptor systems may mediate the actions of the excitatory amino acids.11-15 Three of these receptors, the JV-methyl-D-aspartate (NMDA) receptor, the quisqualate receptor, and the kainate receptor were named after the agonists IV-methyl-D-aspartic acid (3), quisqualic acid (4), and -kainic acid (5), respectively. 16 The fourth, the AP4 receptor, was named for a potent antagonist of specific excitatory pathways of the CNS, namely, L-2-amino-4phosphonobutanoic acid (6). There is increasing evidence that these prototypic pharmacological agents, particularly (2) The slow muscarinic CNS actions of acetylcholine are in marked contrast to its classical millisecond excitatory role for the nicotinic receptors of the vertebrate neuromuscular junction.…”

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confidence: 99%

Excitatory amino acid neurotransmission

Johnson¹,

Koerner

1988

J. Med. Chem.

115

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In the mammalian central nervous system (CNS) there are literally billions of neuronal synapses with each employing a particular neurotransmitter. A neurotransmitter can be either excitatory or inhibitory, depending on whether it produces depolarization or hyperpolarization of the neuronal membrane, respectively. Furthermore, the duration of transmitter action either may be in the low millisecond time range or it may show a prolonged latency and duration of action spanning tenths of seconds or seconds. An attractive model for neuronal organization suggests that there is considerable specificity of the various transmitters for these differing roles.1 While such "classical neurotransmitters" as acetylcholine and the catecholamines, dopamine and norepinephrine, may show either excitatory or inhibitory actions, they also, in most if not all cases, act in the CNS by mechanisms that are of prolonged duration and serve to modulate the intensity of millisecond excitatory or inhibitory impulses.2 Escalating evidence suggests that the neurotransmitter receptors for these systems are coupled to gated ion channels via guanine nucleotide-binding proteins (G proteins) and second messenger intermediates. This mechanism provides great flexibility for adjusting the intensities and durations of many different stimuli. In contrast, millisecond neurotransmitters act on receptors that are coupled to a gated ion channel located on the same transmembrane protein molecule. This arrangement allows microsecond triggering of channel opening in response to binding of the effector molecule. Like the slow-acting modulatory neurotransmitters, millisecond neurotransmitters may also exhibit inhibitory or excitatory effects. For example, the neurotransmitters -aminobutyric acid (GABA) and glycine are thought to be millisecond inhibitory neurotransmitters. However, the most prevalent neurotransmitter class in the mammalian CNS would appear to be the millisecond excitatory neurotransmitters. Foremost among the candidates for millisecond excitatory neurotransmitters in the CNS are the acidic amino acids Lglutamic acid (1) and L-aspartic acid (2).3-6 Glutamic acid, in particular, has been shown to satisfy many of the criteria required for a substance to be designated as a neurotransmitter.7•8 It has been over 30 years since Hayashi9 first reported the convulsant effects of L-glutamic acid and over 25 years

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“…Access to 10 via the thienyllithium, however, required a chlorination step and was low-yielding and inconvenient. Better results were realized via acetimidate 12a , readily prepared by condensing 11a with trimethyl orthoacetate. This protecting group survived tosylation, then cleaved during amination to furnish 13a in about 55% yield from 11a .…”

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confidence: 99%

Enantioselective Synthesis of Brinzolamide (AL-4862), a New Topical Carbonic Anhydrase Inhibitor. The “DCAT Route” to Thiophenesulfonamides

Conrow

Dean

Zinke

et al. 1999

Org. Process Res. Dev.

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A large scale synthesis of the topical carbonic anhydrase inhibitors AL-4623A (13a·HCl) and AL-4862 (13b) from 3-acetyl-2,5-dichlorothiophene (“DCAT”, 1) is described. Reaction of 1 with NaSBn gave thioether 2, which was converted via sulfenyl chloride 3 and sulfenamide 5 to sulfonamide 6. Bromination of 6 gave bromo ketone 7, which upon reduction with (+)-B-chlorodiisopinocampheylborane and cyclization of the resulting bromohydrin produced S thieno[3,2-e]-1,2-thiazine 8a (96% ee) after chromatography. Treatment of 8a in THF with n-BuLi at −70 °C resulted in Li−Cl exchange. Reaction of the thienyllithium with SO2 and hydroxylamine O-sulfonic acid afforded bis-sulfonamide 11a. Protection of 11a as the acetimidate 12a, followed by tosylation and amination, gave R amine 13a. The synthesis of 13b proceeded via primary sulfonamide 16, which was brominated, reduced, and cyclized to give S thieno[3,2-e]-1,2-thiazine 18 (>98% ee). By virtue of the ionizable NH, 18 was separable from reduction byproducts by base extraction. Alkylation of 18 with 3-bromopropyl methyl ether afforded 8b, which was converted as above, via 11b, to AL-4862 (13b). These procedures provided multihundred gram lots of 13a and 13b.

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N-Sulphonylimino Esters

Abstract: not available

Cited by 11 publications

References 0 publications

Metal Free, Microwave Assisted Preparation of N-Sulfonyl and N-Sulfinyl Imines and Imidates

Metal Free, Microwave Assisted Preparation of N-Sulfonyl and N-Sulfinyl Imines and Imidates

Excitatory amino acid neurotransmission

Enantioselective Synthesis of Brinzolamide (AL-4862), a New Topical Carbonic Anhydrase Inhibitor. The “DCAT Route” to Thiophenesulfonamides

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