Nitrones Research Articles

Dimethylzinc‐Promoted Vinylation of Nitrones with Vinylboronic Esters for Pinacol: A New Route to N‐Allylic Hydroxylamines.

Dimethylzinc‐Promoted Vinylation of Nitrones with Vinylboronic Esters for Pinacol: A New Route to N‐Allylic Hydroxylamines.

Synthesis of 2‐Alkenyl‐1‐pyrrolin‐1‐oxides and Polysubstituted Nitrones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The neuroprotective efficacy of NXY-059 in permanent MCAo in the rat: Dose response and therapeutic window

P78 Introduction. NXY-059 (disodium 4-[(tert-butylimino)methyl] benzene-1,3-disulfonate N-oxide) is a nitrone with free radical trapping properties and is being developed for the treatment of acute ischemic stroke. NXY-059 possesses proven neuroprotective efficacy in rat transient models of middle cerebral artery occlusion (MCAo) (J Cereb Blood Flow Metab 1999;19:778–87), however its efficacy in permanent models of focal cerebral ischemia has not been as extensively tested. In the present study we have examined the efficacy of NXY-059 at three doses and further examined the therapeutic window of the mid-range dose. Methods. Adult male Wistar rats (300–330g) were given a unilateral permanent MCAo using an intraluminal suture technique. To assess efficacy of three doses of NXY-059, vehicle or NXY-059 (30, 50 or 70 mg/kg/h) was infused using minipumps for 24 hours. Dosing began 5 minutes after the MCAo with a bolus injection of vehicle or NXY-059 (30, 50 or 70 mg/kg). To assess the therapeutic window, treatment with 50 mg/kg (loading dose) and 50 mg/kg/h (over 24 hours) NXY-059 was commenced at 5, 30, 60, 120 and 240 minutes after MCAo. For both assessments, brains were removed 24 hours after commencing treatment and volume of damage was calculated from 5 x 2mm sections stained with triphenyl tetrazolium chloride. Results. NXY-059 (30, 50 and 70 mg/kg/h) reduced the volume of damage by 23%, 57% and 81% respectively (p Conclusions. In rats given a permanent MCA occlusion, NXY-059 at doses of 30–70 mg/kg/h given for 24 hours significantly (p

Two New Methodologies for the Deoxygenation and Reduction of Nitrones Based on the Use of Lithium and DTBB (cat.) ‡

Two New Methodologies for the Deoxygenation and Reduction of Nitrones Based on the Use of Lithium and DTBB (cat.) ‡

Effects of phenyl N-tert-butyl nitrone and its derivatives on hepatocarcinogenesis in rats fed a choline-deficient, L-amino acid-defined diet.

Effects of phenyl N-tert-butyl nitrone and its derivatives on hepatocarcinogenesis in rats fed a choline-deficient, L-amino acid-defined diet.

Polymeric nitrones, 1. Synthesis and modification of polymeric nitrones derived from polymerizable aldehydes

The model compound N,C-diphenylnitrone[N-(benzylidene)aniline-N-oxide] (3) was prepared by condensation of benzaldehyde with phenylhydroxylamine to study its thermal stability. X-ray diffraction analysis of a single crystal established the conformation of the nitrone group. A new monomer 4-(methacryloyloxy)benzaldehyde-phenylnitrone (8) was also prepared and could not be polymerized with 2,2′-azobisisobutyronitrile (AIBN) as initiator at 70°C. Under these conditions the nitrone reacted exclusively in an intermolecular 1,3-dipolar cycloaddition to give oligomeric tetrahydro-1,2-oxazoline derivates. The kinetics of the cycloaddition was investigated. Additionally, different (meth)acryl- and styryl-substituted aldehyde monomers were synthesized: N-(2-methacryloyloxyethyl)-N-ethyl-4-aminobenzaldehyde (19 a), N-(2-acryloyloxyethyl)-N-ethyl-4-aminobenzaldehyde (19 b), 2-(N′-ethyl-4-formylanilino)ethyl N-(α,α-dimethyl-3-isopropenylbenzyl)carbamate (20) and 4-(3-methacryloyloxypropoxy)benzaldehyde (25). These new monomers were homo- and copolymerized with MMA radically at 70°C using AIBN as initiator. The resulting polyaldehydes 26–30 were reacted with phenylhydroxylamine to obtain the polynitrones 31–35 in yields of up to 95%. The obtained highly polar polynitrones 31–32 were modified by irradiation with UV-light.

A Route to (2α,3β,4α)-(±)-2-(Hydroxymethyl)-3,4-pyrrolidinediol Based on the α-Silyloxyallylation of a Glycolaldehyde-Derived Nitrone

A Route to (2α,3β,4α)-(±)-2-(Hydroxymethyl)-3,4-pyrrolidinediol Based on the α-Silyloxyallylation of a Glycolaldehyde-Derived Nitrone

Azulenyl Nitrone Spin Traps Protect against MPTP Neurotoxicity

Azulenyl nitrones are a unique class of free radical spin-trapping compounds. We administered both a water-soluble and a lipid-soluble azulenyl nitrone to mice prior to administration of MPTP. Both compounds produced significant neuroprotection against depletions of dopamine and its metabolites measured 1 week after MPTP administration. There were no effects on MPP+levels. These findings provide further evidence that free radical scavengers can produce significant neuroprotection against MPTP neurotoxicity.

Catalytic Enantioselective 1,3-Dipolar Cycloadditions between Nitrones and Alkenes Using a Novel Heterochiral Ytterbium(III) Catalyst

Catalytic Enantioselective 1,3-Dipolar Cycloadditions between Nitrones and Alkenes Using a Novel Heterochiral Ytterbium(III) Catalyst

Synthesis of a 1-benzylpiperazin-2-one nitrone and its reaction with alkynes and alkenes

A novel 1-benzylpiperazin-2-one nitrone has been synthesized. It readily undergoes [3+2] cycloadditions with alkynes and alkenes to give Δ 4-isoxazolines and isoxazolidines, respectively, which can be reductively opened to 3-substituted piperazin-2-ones and 1,3-amino alcohols.

Synthesis of Alkynyl-Substituted Pyrrolidin-1-yloxyl Radicals from 1-Pyrroline N-Oxide Nitrones and Alkynylmagnesium Bromides

Synthesis of Alkynyl-Substituted Pyrrolidin-1-yloxyl Radicals from 1-Pyrroline N-Oxide Nitrones and Alkynylmagnesium Bromides

On the Regiochemistry of Cycloaddition of Unsymmetrical Aryne with Nitrone Remarkable Effect of Trialkylsilyl Substituent

On the Regiochemistry of Cycloaddition of Unsymmetrical Aryne with Nitrone Remarkable Effect of Trialkylsilyl Substituent

Structure of N-methyl benzaldehyde nitrone

Structure of N-methyl benzaldehyde nitrone

ChemInform Abstract: (6π + 4π)Cycloadditions of 5‐Azoniafulvene Ions with Nitrones and Azomethinimines.

AbstractThe ammonium salt (I) reacts with the nitrones (II), producing the pyrroloxadiazines (III).

One-electron cleavage of sulphones in the presence of nitrones as spin traps

One-electron cleavage of sulphones in the presence of nitrones as spin traps

ChemInform Abstract: Employment of Nitriles in the Stereoselective Cycloaddition to Nitrones.

Reaction de dinitriles gemines et de nitrones: obtention regioselective d'oxadiazole-1,2,4ines-4

ChemInform Abstract: O‐ and C‐Stannylation of Nitroalkanes.

AbstractThe nitroalkanes (I) and the bisstannyl oxides (II) form mainly the nitronates (III), together with the α‐stannylated nitroalkanes (IV).

O- and C-stannylation of nitroalkanes

Stannlylation of nitroalkanes by tributylstannyl amides and bis(tributylstannyl) or bis(triphenylstannyl) oxides has been found to give mainly tin nitronates. Some C-stannylated species have been also characterized.

Regioselective Effects of the Allylic Heteroatoms in 1,3-Dipolar Cycloaddition of Nitrones to Several Allyl Derivativea

L'atome d'oxygene allylique modifie la regioselectivite dans la cycloaddition dipolaire-1,3 de nitrones pour donner les alcoxymethyl-4 isoxazolidines. La selectivite n'est pas modifiee par la geometrie des dipolarophiles

Ketene. Part 26. The reactions of 3,4-dihydroisoquinoline N-oxide with ketenes, and an attempted synthesis of 3,4-dihydro-3,3-dimethylquinoline N-oxide

3,4-Dihydroisoquinoline N-oxide reacts with dimethylketene to form a 1 : 2 adduct (8) in addition to compounds (6) and (7). With cyano-t-butylketene and ethoxycarbonyl-t-butylketene the adducts (9a) and (9b) are formed. 3,3-Dimethyl-1,2,3,4-tetrahydroquinoline (21a) has been synthesized, but attempts to convert this into the nitrone (20b) were unsuccessful.