Substituent effects on the isomer ratios in the rearrangement of some 2- and 4-nitraminopyridines

Deady, LW; Korytsky, OL; Rowe, JE

doi:10.1071/ch9822025

Cited by 24 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An additional procedure for the synthesis of compound 7 has recently been published by Tian and co‐workers 24. The synthesis of compound 16 starting from 15 was established by our group since 1999;19 it is based on a synthesis developed by Rowe and co‐workers 25…”

Section: Methodsmentioning

confidence: 99%

Second‐Generation Supramolecular Dendrimer with a Defined Structure due to Orthogonal Binding

Eckelmann

Dethlefs

Brammer

et al. 2012

Chemistry A European J

View full text Add to dashboard Cite

A second-generation supramolecular dendrimer has been prepared by orthogonal multiple hydrogen bonding. In the first (inner) recognition domain, the interaction of one bis-isocyanuric acid (25) with two branching units (21) that carry complementary Hamilton receptors has been exploited. In the second (outer) generation, the two ADDA (A=hydrogen-bond acceptor, D=donor) receptors of each branching unit (21) have bound complementary DAAD units (4). The problem of limited solubility of the building blocks has been overcome by the introduction of branched ethylhexyl residues and by the use of flexible alkylene or oligo(ethylene glycol) linking chains. The orthogonal binding of the two hydrogen-bonding pairs was elucidated by chemical induced shift NMR titrations, which proved that the two pairs, isocyanuric acid with the Hamilton receptor and ADDA with DAAD, bind preferentially. The formation of the supramolecular self-assembled 1:2:4 dendrimer with a molecular weight of 5065 g mol(-1) was investigated by diffusion NMR spectroscopy.

show abstract

Section: Methodsmentioning

confidence: 99%

Second‐Generation Supramolecular Dendrimer with a Defined Structure due to Orthogonal Binding

Eckelmann

Dethlefs

Brammer

et al. 2012

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…[41] 2-Amino-4-tert-butylpyridine [53] and 2-amino-4-methoxypyridine [54] were prepared according published methods. All other compounds and reagents were obtained from commercial suppliers and used without further purification.…”

Section: Methodsmentioning

confidence: 99%

Living Radical Polymerization of Acrylates Mediated by 1,3‐Bis(2‐pyridylimino)isoindolatocobalt(II) Complexes: Monitoring the Chain Growth at the Metal

Langlotz

Lloret‐Fillol

Gross

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

A new type of mediator for cobalt(II)-mediated radical polymerization is reported which is based on 1,3-bis(2-pyridylimino)isoindolate (bpi) as ancillary ligand. The modular synthesis of the bis(pyridylimino)isoindoles (bpiH) employed in this work is based on the condensation of 2-aminopyridines with phthalodinitriles. Reaction of the bpiH protio-ligands with a twofold excess of cobalt(II) acetate or cobalt(II) acetylacetonate in methanol gave [Co(bpi)(OAc)], which crystallize as coordination polymers, and a series of [Co(acac)(bpi)(MeOH)], which are mononuclear octahedral complexes. Upon heating the [Co(acac)(bpi)(MeOH)] compounds to 100 degrees C under high vacuum, the coordinated methanol was removed to give the five-coordinate complexes [Co(acac)(bpi)]. The polymerization of methyl acrylate at 60 degrees C was investigated by using one molar equivalent of the relatively short-lived radical source 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) as initiator (monomer/catalyst/V-70: 600:1:1). The low solubility of the acetato complexes inhibits their significant activity as mediators in this reaction, whereas the acetylacetonate complexes control the radical polymerization of methyl acrylate more effectively. The radical polymerizations of the hexacoordinate complexes did not show a linear increase in number-average molecular weight (M(n)) with conversion; however, the polydispersities were relatively low (PDI=1.12-1.40). By using the pentacoordinate complexes [Co(acac)(bpi)] as mediators, a linear increase in M(n) values with conversion, which were very close to the theoretical values for living systems, and very low polydispersities (PDI<1.13) were obtained. This was also achieved in the block copolymerization of methyl acrylate and n-butyl acrylate. The intermediates with the growing acrylate polymer radical ((.)PA) were identified by liquid injection field desorption/ionization mass spectrometry as following the general formula [Co(acac)(4-methoxy-bpi)-(MA)(n)-R] (MA: methyl acrylate; R: C(CH(3))(CH(2)C(CH(3))(2)OCH(3))CN), a notion also confirmed by NMR end-group analysis.

show abstract

“…This gave 0.633 g of an oil, which was purified by flash chromatography (2 % acetone in dichloromethane) to give 0.189 g (>98 % pure by 1 : δ 13.9, 19. 8, 21.8, 31.1, 69.7, 94.2, 125.2, 141.0, 150.6, 152.0, 162.1 ppm; one (18), 211 (100), 208 (10), 206 (5), 198 (18), 193 (6), 192 (5), 181 (19), 168 (11), 167 (67), 166 (18), 163 (15), 122 (5), 121 (48), 120 (11), 119 (5), 106 (7), 94 (5), 93 (7), 92 (5), 67 (7), 45 (11), 43 (28) ppm; hrms: observed: M + 296.1478. Calculated for C 1 3 H 2 0 N 4 O 4 : 2 9 6 .…”

Section: Methods Amentioning

confidence: 99%

“…By substitution of the chloro moiety, NH 2 , OMe, and other groups have been introduced in the 6-position [16][17]. Substitution of the chloro with a methoxy group p r i o r t o nitration has also been reported [18]. No yield was given for the NAS step.…”

Section: Introductionmentioning

confidence: 99%

Preparation of substituted 1,3‐dihydro‐2H‐imidazo[4,5‐c]pyridin‐2‐ones

Bakke

Gautun

Svensen

2003

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

A new synthetic route to 6-substituted-imidazo [4,5-c]pyridin-2-ons from 4-aminopyridine has been investigated. 4-Aminopyridine protected as alkyl carbamates were nitrated with dinitrogen pentoxide to the corresponding methyl, i-propyl and t-butyl 3-nitropyridin-4-yl carbamates (5 a-c) in 51-63 % yields. Attempts to substitute these in the 6-position by the ONSH and the VNS techniques succeeded with butylamine and the t-butyl carbamate 9.

show abstract

Substituent effects on the isomer ratios in the rearrangement of some 2- and 4-nitraminopyridines

Cited by 24 publications

References 0 publications

Second‐Generation Supramolecular Dendrimer with a Defined Structure due to Orthogonal Binding

Second‐Generation Supramolecular Dendrimer with a Defined Structure due to Orthogonal Binding

Living Radical Polymerization of Acrylates Mediated by 1,3‐Bis(2‐pyridylimino)isoindolatocobalt(II) Complexes: Monitoring the Chain Growth at the Metal

Preparation of substituted 1,3‐dihydro‐2H‐imidazo[4,5‐c]pyridin‐2‐ones

Contact Info

Product

Resources

About