bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal complexes of 1,10-phenanthroline derivatives. XI. Complexes of 1,10-Phenanthroline-2,9-di(carbaldehyde phenylhydrazone)
Authors: Abushamleh AS , Goodwin HA
Published: September 2010

1,10-Phenanthroline-2,9-dicarbaldehyde
has been prepared by oxidation of 2,9-dimethyl-1,10-phenanthroline with
selenium dioxide. The value of the dialdehyde in the synthesis of open-chain
multidentate chelating agents has been examined and the function of the di(phenylhydrazone) derivative is described. Steric
constraints within the molecule render quadridentate function difficult and a
distinct tendency to tridentate coordination is observed. Complexes of the
dihydrazone with bivalent iron, cobalt, nickel and copper are described.
Carbon-13 N.M.R. spectra of some 1-substituted azulenes
Authors: Wells PR , Penman KG , Rae ID
Published: September 2010

The 13C n.m.r.
spectra of 1-R-azulenes, where R = NO2, CN, COCH3, COCF3,
Br, OMe, OCOPh and NH2,
have been assigned by comparison with other aromatic systems and by
consideration of C-H couplings in the fully coupled 13C spectra.
Substituent chemical shifts were obtained for all carbons.
Perchlorate and difluorophosphate coordination derivatives of rhenium carbonyl
Authors: Horn E , Snow MR
Published: September 2010

The complexes Re(CO)5ClO4,
Re(CO)5PO2F2, L2(CO)3Re(OClO3)
and L2(CO)3Re(PO2F2), where L2
= 2,2?-bipyridyl (bpy), have been synthesized by
bromide abstraction reactions from the respective rhenium carbonyl bromide
precursors. The complexes were characterized by infrared and mass spectroscopy.
The crystal structure of (bpy)(CO)3Re(PO2F2)
has been determined from X-ray diffraction data by the heavy-atom technique.
The crystals are triclinic, space group Pī with
a 8.620(3), b 15.912(5), c 6.466(3) Ǻ, α 102.08(8), β 83.29(8),
γ 95.08(4) and Z 2. The structure has been refined by full-matrix
least-squares from 2829 reflections to R = 0.084, Rw = 0.088. The
coordination geometry about rhenium is that of a distorted octahedron. Difluorophosphate coordinates to the metal centre by one of
its oxygen atoms. Formation of the difluorophosphate
by hydrolysis of hexafluorophosphate was shown by 31P n.m.r.
spectra.
1H, 13C and 195Pt n.m.r. spectra of Trimethylplatinum(IV) Tetramers [PtMe3Z]4: effects of Pt-Z-Pt and long-range Pt-Z-Pt-C couplings
Authors: Appleton TG , Hall JR
Published: September 2010

1H, 13C and 195Pt n.m.r. spectra
have been obtained for [PtMe3(μ3-Z)]4 (Z
= Cl, Br, I, OH, N3, SMe,
SPh, and SCF3). The compounds with Z = SPh and SCF3 have not previously been prepared. In
those tetramers which contain more than one 195Pt nucleus, and where
195Pt-Z-195Pt coupling is significant, 1H and 13C
spectra cannot be interpreted as first order. Values of 2JPt-Z-Pt
have been calculated from 13C spectra where Z = SMe,
SPh, OH, and N3, and upper limits
estimated for a number of other Z. When Z = SMe and
OH, long-range 195Pt-Z-Pt-13C coupling is resolved. 2J(195Pt-S-13C)
when Z = SMe and SCF3, and 3J(195Pt-S-C-19F)
when Z = SCF3, are unexpectedly small. The 195Pt
resonance frequency decreases in the order Z = OH > SPh
> SMe > N3 ≈ Cl > Br ≈ SCF3 > I. To assist in
analysing the spectra transition frequencies and intensities have been
calculated for the AA'2X spectrum (available as an accessory publication).
Synthesis and carbon 13 N.M.R. spectrum of the peptide fragment of myelin basic protein (human)
Authors: Pasaribu SJ
Published: September 2010

The tridecapeptide Phe-Lys-Leu-Gly-Gly-Arg-Asp-Ser-Arg-Ser-Gly-Ser-Pro- OH,
and its methyl ester derivative at the carboxyl terminal, -Pro-OMe,�were
synthesized by the solution-phase method. The synthesis was accomplished by
fragment condensation of a tetrapeptide, Boc-Phe- Lys(N8-Cbz)-Leu-Gly-OH,
and a nonapeptide, H-Gly-Arg(NO2)-Asp(OBzl)- Ser(OBzl)-Arg(NO2)-Ser(OBzl)-Gly-Ser(OBzl)-Pro-OR (R = Me or Bzl), in the presence of dicyclohexylcarbodiimide and
benzo-triazol-1-ol, to give the protected tridecapeptide. This compound, when
OR = OBzl, was hydrogenated at room temperature, with
Pd/C as catalyst, followed by treatment with boron tristrifluoro-acetate to
remove all the protecting groups. When OR = OMe, the
final product was the methyl ester of the tridecapeptide. The mixed anhydride
method (REMA) was followed in the synthesis of the intermediates. 13C
n.m.r. spectra of the tridecapeptide and of the peptide intermediates are
discussed.
Photochemistry of azole N-oxides. III. Photoinduced ring expansion of 2H-1,2,3-Triazole N-oxides
Authors: Gainsford GJ , Woolhouse AD
Published: September 2010

Triaryl-4H-1,3,4,5-oxatriazines,
the first members of the general class of oxatriazine heterocycles, have been
isolated in high yields from the ultraviolet photolyses of the corresponding
triaryl-2H-1,2,3-triazole N-oxides. Crystallographic parameters on one such
1,3,4,5-oxatriazine are also presented.
Allylic nucleophilic substitution reactions in sugars. III. Uncatalysed displacements in hexamethylphosphoramide
Authors: Guthrie RD , Irvine RW , Jenkins ID
Published: September 2010

The uncatalysed
displacement of allylic benzoyloxy groups with azide in unsaturated sugars has
been studied by using hexamethylphosphoramide as solvent. Tri-O-benzoylglycals and 4,6-O-benzylidene-3-O-benzoylglycals
were investigated. The former gave rise to mixtures of 3-azido-glycals and
hex-2-enopyranosyl azides, whereas the latter gave only glycal
products. The mechanism of the reactions is considered in some detail.
Displacements on allylic trimethylsilyl ethers were not successful.
19F N.M.R. chemical shifts in substituted benzotrifluorides and benzal fluorides
Authors: Brownlee RTC , Craik DJ
Published: September 2010

19F substituent chemical shifts (scs)
for a series of meta and para benzotrifluorides (p-trifluoromethyl-benzenes) are reported and are found to
follow the reverse scs trend previously noted for
benzyl fluorides (fluoromethylbenzenes), i.e. donors
cause downfield shifts and acceptors upfield ones. Specific deviations for
electron- withdrawing substituents make DSP correlations for the benzo-
trifluorides less precise than for benzyl fluorides. A series of p- benzal
fluorides (p-difluoromethyl-benzenes) has also been synthesized and the scs values are also found to follow the reverse trend. The
magnitude of scs values decreases in the sequence
benzyl fluorides > benzal fluorides
> benzo-trifluorides.
Studies in the tricyclooctane series. VI. Dehydrohalogenation of 8,8-dihalobicyclo[5,1,0]octa-2,4-dienes : Plausible intermediates in the tricyclooctane-styrene conversion
Authors: Banwell MG , Halton B
Published: September 2010

The dehydrohalogenation of
8,8-dichloro- and 8,8-dibromo- bicyclo[5,1,0]octa-2,4-diene (4c,d)gives rise to
the (E)- and (Z)-isomers of β-t-butoxystyrene
(2c). Plausible pathways for the conversion are discussed and evidence in
support of bicyclo[4,2,0]octa- 2,4-dienes as
intermediates in the conversion is presented. The results support the
intervention of halobicyclo[5,1,0]octa-2,4-dienes in the conversion of tetra-
and tri-halo-cis-transoid-cis- tricyclo[5,1,0,03,5]octanes (1a-d) to
styrenes(2a-c).
Central nervous system active compounds. V. Claisen rearrangement products of allyl vinyl ethers obtained from caprolactam derivatives
Authors: Mooney BA , Prager RH , Ward AD
Published: September 2010

A series of allyloxy
unsaturated tetrahydroazepinones has been prepared and their Claisen rearrangements
have been investigated. The 4-allyloxy compounds (4a-e) rearranged thermally to
give the 3-substituted hexahydro derivatives (9). In some cases further
reaction products were obtained, particularly when higher temperatures were
used. Rearrangement of the 4-propargyloxy system (4f) proved more complicated,
and N-allyl-2,3,4,5-tetrahydro-1H-azepin-2-one derivatives (21a,b) were
unreactive. Alkylation of the hexahydroazepine-2,4-dione system (3) with
various allyl halides gave mixtures of the 3-mono-(20) and the
3,3-di-substituted (19) products. The unsaturated ethers generally showed
marked muscular depression on the central nervous system of mice, while their
rearrangement products were only weakly depressant.
Synthesis of (6α-2H)- and (6β-2H)-Cholest-4-en-3-one
Authors: Collins DJ , Jackson WR , Timms RN
Published: September 2010

Good experimental
procedures for the preparation of both (6α-2H)- and (6β-2H)-cholest-4-en-3-one
are described, based on modification of methods described by Nambara and his
coworkers. In addition, some less satisfactory literature methods are commented
on and experiments based upon two proposed short, but unsuccessful, routes are
described.
Organocuprates as electron transfer reagents. Evaluation for conjugate addition of electrophiles to α,β-unsaturated ketones
Authors: Hannah DJ , Smith RAJ , Teoh I , Weavers RT
Published: September 2010

The reaction of a series of
organocuprate systems containing alkyl, aryl, alkynyl, silylalkyl or phenylthio
groups with (1) is reported. Some of these organocuprates
showed electron transfer properties and were relatively unreactive
toward conjugate addition, hence have potential synthetic application as organocuprates involving an external electrophile.
The synthesis and kinetics of isomerization and solvent exchange of the trans-Chloro(dimethyl sulfoxide)bis(ethylenediamine)cobalt(III) ion in dimethyl sulfoxide
Authors: Jackson WG
Published: September 2010

The synthesis and
characterization of trans-[CO(en)2(Me2SO)Cl](ClO4)2
are described. Its rate of isomerization to the cis isomer has been measured in Me2SO in the range
293-313 K: ktc
= 1.54 × 10-3s-1 at 298.2 K, ΔH‡ = 105 kJ
mol-1, ΔS‡ = 55 J mol-1 K-1. The solvent
exchange rate has been measured by 1H n.m.r. spectroscopy in (CD3)2SO
at 308.2K: kex = ktt+ktc
= 7.0xl0-3 s-1. These and other data show that trans-to-cis isomerization requires solvent exchange, each act of which
leads to substantial rearrangement, c.
90% cis (308.2 K). Differences
between non-aqueous and aqueous systems in the steric course of substitution
are discussed.
Supersonically expanding reacting flows : the chemiluminescent Sn/N2O reaction
Authors: Mackie JC , Nicholls J
Published: September 2010

A supersonic flow reactor
comprising a shock tube and convergent-divergent expansion nozzle has been
developed and used to study the chemiluminescent
reaction between tin atoms and nitrous oxide. The reaction has been found to
excite the a-X, b-X and A-X transitions of SnO and
rate constants for formation of the three excited states have been found to
have the same activation energy, 25�5 kJ mol-1. Estimates of
branching ratios have been made on the basis of experimental measurement and
kinetic modelling and an assessment of the Sn/N2O
reaction as a possible electronic chemical laser is made.
Site- and stereo-selectivity in the reaction of bicyclo[4,2,0]octa-2,4-dienes and related 2,4,7-trienes with 3-chloroperbenzoic acid: the formation ofacid-sensitive ene-epoxides and their conversion into 1,4-epoxides
Authors: Tan RYS , Russell RA , Warrener RN
Published: September 2010

Controlled site selective
peroxidation of the bicyclo[4,2,0]octa-2,4,7-trienes (1a), (1b) or the related
2,4-diene (9) by means of 3-chloroperbenzoic acid in a basic two-phase medium
allows the isolation of ene epoxides; these are especially sensitive to acid
and rearrange to 1,4-oxides upon treatment with commercial (D)chloroform.
Regular 3-chloroperbenzoic acid peroxidation conditions yield the 1,4-oxides
directly. A carbonium mechanism is proposed to account for the interconversion
of the initially formed 1,2-oxides into the more stable 1,4-oxides; the
benzocyclobutene and methylene alcohols isolated in some cases are accommodated
within this mechanism. Structure determinations draw heavily on 13C
n.m.r. spectroscopy, especially to distinguish between epoxides and 1,4-oxides.
The X-ray structure of a key 1,4-Coxide (11) is presented. The concept of the
steric bulk of a π-cloud is discussed in terms of its role in controlling the
stereoselectivity of the epoxidation reaction.
The structure of connorstictic acid. A depsidone from the lichen Lecidea aspidula
Authors: Elix JA , Lajide L
Published: September 2010

Connorstictic acid (2) was
isolated from the lichen Lecidea aspidula
as the corresponding tetraacetate(3). The structure of the latter compound was
confirmed by synthesis in several steps from the known depsidone, norstictic
acid (4). Direct reduction of norstictic acid with sodium triacetoxyborohydride
led to the formation of connorstictic acid.
The synthesis of alkyl- and aryl-substituted 1,3,5-triazines
Authors: Harris RLN
Published: September 2010

The reaction of
chloromethyleneiminium salts with N-cyanoamidines
provides a new and versatile route to alkyl- and aryl-substituted
1,3,5-triazines. Variation of substituents in the starting materials allows the
synthesis of monoaryl-, diaryl-, alkyl-aryl- and certain mono- and
di-alkyl-l,3,5-triazines bearing a variety of other substituents including
hydrogen, chlorine and O-, S- and N-radicals. The generally good yields, ready
availability of starting materials, and the scope and facility of the reaction make
it the method of choice for the synthesis of 1,3,5-triazines with these
substitution patterns.
New synthesis of benzotriazole photostabilizers
Authors: Evans NA
Published: September 2010

1-(2-Nitrophenyl)-5-aryltetrazoles
and 1-aryl-5(2nitropheny1)tetrazoles are converted into 2-arylbenzotriazoles by
the action of heat, the former reacting much faster than the latter. By
appropriate use of methoxyl groups, useful benzotriazole ultraviolet absorbers
may be synthesized conveniently by this method.
Syntheses of some thiol esters for acylation of proteins
Authors: Dalton JR , Kirkpatrick A , Maclaren JA
Published: September 2010

A series of thiol esters,
and S-esters of thiocarbamic acid,
has been prepared by making mercapto-acetic acid or 2-mercaptoethanesulfonic
acid react with carboxylic acid chlorides or with isocyanates. Aqueous
solutions of these products are stable to hydrolysis but rapidly acylate
amines. Azo-dyes that incorporate these reactive groups have been synthesized.
Isolation, crystal structure and synthesis of arsenobetaine, a constituent of the western rock lobster, the dusky shark, and some samples of human urine
Authors: Cannon JR , Edmonds JS , Francesconi KA , Raston CL , Saunders JB , Skelton BW , White AH
Published: September 2010

Arsenobetaine has been
isolated from the tail muscle of the western rock lobster (Panulirus cygnus George) and from the flesh of the dusky shark (Carcharhinus obscurus Le Sueur), both of
which are commercially important seafoods. Trigonelline has also been isolated
from the lobster and both arsenobetaine and trigonelline have been isolated
from human urine obtained after ingestion of cooked rock lobster. The crystal
structures of the monohydrates of arsenobetaine and trigonelline have been
determined and a simple synthesis of arsenobetaine has been developed.
Reaction of isothiocyanates with thiourea - a correction
Authors: Joshua CP , Prasannan E , Thomas SK
Published: September 2010

The condensation products
of isothiocyanates with thiourea reported to be S-(N-substituted
thiocarbamoyl)isothioureas are in fact 1- substituted 2,4-dithiobiurets and not
the former. The condensation of isothiocyanates with 1-substituted thioureas
also is found to yield 1,5-disubstituted 2,4-dithiobiurets. The structures were
verified by comparison with authentic samples and chemical reactions.
The chemistry of Dodonaea spp. VIII. Isolation and crystal structure of a diterpene acid from Dodonaea petiolaris
Authors: Jefferies PR , Payne TG , Raston CL , White AH
Published: September 2010

On the basis of physical
data, an acid isolated from the title plant is found to be ent-3β-acetoxy-
15,16-epoxylabda-8(17),13(16),14-trien-18-oic acid (1) or its enantiomer. The crystal
structure of the acid, C22H28O6, was
determined from single-crystal diffractometer data at 295(1) K, being refined
by least squares to a residual of 0·056 for 922 'observed' reflections;
crystals are orthorhombic, P212121, a 16·22(1), b 12·212(5), c 9·976(3)
�, Z 4.
3-Methoxy-2,4-di-O-methylgyrophoric acid: a novel tridepside from the lichen Parmelia subfatiscens
Authors: Elix JA , Jayanthi VK
Published: September 2010

The title compound has been
isolated, characterized and the structure confirmed by total synthesis.
Phosphorus-31, cadmium-113 and mercury-199 N.M.R. studies on dithiolate complexes of cadmium and mercury and their phosphine adducts
Authors: Bond AM , Colton R , Dakternieks D , Dillon ML , Hauenstein J , Moir JE
Published: September 2010

Phosphorus-31, cadmium-113
and mercury-199 n.m.r. spectra have been recorded for a series of O,O-dialkyldithiophosphate (dtp) and dialkyldithiocarbamate (dtc)
complexes of cadmium and mercury in dichloromethane solution. Both types of
ligand are labile on the n.m.r. time scale at room temperature, although the
exchange of dtc ligands can be slowed at low
temperatures. .The complexes interact with
tributylphosphine and tricyclohexylphosphine (pcy), but at room temperature the phosphines are also
labile. At low temperatures, however, the phosphine exchange becomes slow on
the n.m.r. time scale to allow identification of the adducts except for Cd(dtc)2 adducts with
PBu3 which are still labile at -110°C. All the data indicate that cadmium has a
lower affinity for phosphine than mercury and that dtc
ligands are more strongly bound to the metals than dtp
ligands.
The chemistry of Eremophila spp. XV. New acyclic diterpenes from Eremophila spp
Authors: Ghisalberti EL , Jefferies PR , Proudfoot GM
Published: September 2010

Eight new acyclic
diterpenes have been isolated from the resin of E. exilifolia
F. Muell., E. glutinosa Chinnock and E. glutinosa var.
Evidence for their structure is presented. In contrast to most other acyclic
diterpenes those from Eremophila species contain two internal double bonds in
the cis-configuration with respect to the carbon chain. The biosynthetic
significance of these compounds is discussed.
Generation of tris(4-dimethylaminophenyl)methanol (crystal violet carbinol) in reversed micelles
Authors: Miyoshi N , Tomita G
Published: September 2010

The carbinol
of crystal violet* (cv) was readily generated in
dodecylammonium propionate (dap) reversed micellar solutions even when aqueous cv solutions at highly acidic pH were solubilized. This was
confirmed from the absorption and fluorescence measurements. The carbinol reaction depended strongly on the solubilized H2O
content.
Nonadditive carbon-13 nuclear magnetic resonance substituent shifts in 1,4-disubstituted benzenes. Application of the DSP-NLR equation to the OCOCH3, CONH2 and CSNH2 series
Authors: Brownlee RTC , Sadek M
Published: September 2010

Carbon-13 Substituent
Chemical Shifts (SCS) for all the ring carbons for a series of para-substituted
phenyl acetates, benzamides, and thiobenzamides are reported. The measurements
were made under standard conditions at low concentration (in deuterochloroform
for the acetates, and (CD3)2SO for the amides) and data
are reported for an extensive range of para substituents (NMe2, NH2,
OCH3, OCOCH3, F, Cl, Br, Me, H,
CF3, CN, COOR, COCH3, NO2, CHO). The observed
non-additive substituent chemical shifts have been interpreted in terms of
variation of the Shift Charge Ratio and mutual substituent interaction. The
substituent constants σI and σ0R
for OCOCH3, CONH2, CSNH2 substituents are
determined and compared with previously published data. Electronic properties of
OCOCH3, OCH3 substituents and CONH2, CSNH2
substituents are discussed. The self-consistency and advantages of the Dual
Substituent Parameter equation (DSP) and the recently developed
Non-Linear-Resonance equation (DSP-NLR) treatments of 13C SCS data
are discussed, and contrasted with an alternative single parameter approach.
New quinolinone alkaloids from the heartwood of, Euxylophora paraensis
Authors: Jurd L , Wong RY
Published: September 2010

The heartwood of
Euxylophora paraensis Hub. (Rutaceae) has given N-methylflindersine
(2),spectabiline (3), skimmianine (4) and two new alkaloids, identified from
spectroscopic data as 4-hydroxy-2,2,6-trimethyl-3,4,5,6-tetrahydro-2H-pyrano[3,2-c]quinolin-5-one
(5) and 4-(2,3-dihydroxy-3-methylbutoxy)-1-methylquinolin-2(1H)-one (6). Five
new dimeric quinolinone alkaloids, C30H30N2O4,
were isolated. The structure of one of these, paraensidimerin D, has now been
shown by single-crystal X-ray diffraction methods to be (11), viz.
(6aα,7α,14aα)-6,6,9,16- tetramethyl-7-(2-methylprop-1-enyl)-6,6a,7,9,14a,16-hexahydro-8H,15H-
quino[3'',4'':5',6'] pyrano [2',3':4,5] pyrano-[3,2-c]quinoline-8,15- dione.
Synthesis and evaluation of fluorescent materials for colour control of peroxyoxalate chemiluminescence. III. Yellow and red fluorescent emitters
Authors: Hanhela PJ , Paul DB
Published: September 2010

A number of
bis(phenylethynyl)-substituted anthracenes and naphthacenes have been
synthesized and their suitability as fluorescent additives for peroxyoxalate
chemiluminescence evaluated. Fluorescence and chemiluminescence emission data
for all compounds are presented. Both 2-chloro- and
6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet
chemiluminescence with the peroxyoxalate system (λmax 609 and
614 nm respectively). Although solutions of both compounds decolorize slowly in
the presence of air and light, when used in concentrations of 1-5 × 10-3M
they allow efficient chemiluminescence for greater than 5 h.
Pterins. VII. Preparation of 6,6-dimethyl-5,6,7,8-tetrahydropterin hydrochloride
Authors: Armarego WLF , Waring P
Published: September 2010

The preparation of
6,6-dimethyl-5,6,7,8-tetrahydropterin (5) hydrochloride, a possible substrate
for the phenylalanine hydroxylating system, has been
achieved by trimethylsilylating 6-methyl-7,8- dihydropterin, reacting with methyllithium
and removing the trimethylsilyl groups. Attempts to
prepare this pterin by intramolecular cyclization of
2,5-diamino-6-(2'-hydroxy-2'-methylpropyl)-aminopyrimidin-4(3H)-one (17) gave the isomeric
5,8-diamino-3,3-dimethyl-2,3-dihydroimidazo- [1,2-clpyrimidin-7(1H)-one (20).
Protected amino acid active esters incorporating the 4-picolyl basic solubilizing group
Authors: Stewart FHC
Published: September 2010

The 4-picolyl ester of
4-hydroxy-3-nitrophenylacetic acid has been prepared from an active polyester intermediate,
and used as the precursor of a series of protected amino acid active esters.
Thesecompounds were satisfactory
coupling components in peptide syntheses. Purification of the protected peptides
by acid washing was facilitated by the presence of the basic 4-picolyl moiety.
Structural and spectroscopic studies of transition metal nitrite complexes. IV. Crystal structure and spectra of cis-Aquabis[N,N-dimethyl(ethane-1,2-diamine)]-nitronickel(II) perchlorate
Authors: Finney AJ , Hitchman MA , Raston CL , Rowbottom GL , White AH
Published: September 2010

The crystal and molecular structure of
the complex cis-aquabis[N,N-dimethyl(ethane-l,2-diamine)]- nitronickel(11) perchlorate is
reported and the stereochemistry is compared with those observed for other
nickel nitrite complexes formed by substituted amines. The electronic spectrum
of the complex in the visible region is unusual, showing bands with maxima at
17750 and 21000 cm-1. The latter peak consists of a poorly resolved vibrational progression having an interval of c.600cm-1.
While the lower energy band is assigned to the second spin-allowed 'd-d'
transition of an octahedral nickel(11) complex, it is suggested that the band
at 21000 cm-1 is due either to a metal → ligand
charge-transfer transition, or to an internal n(O)→ π* nitrite transition.
Conformational analysis of coordination compounds. XII. N- and C-Substituted five-membered diamine chelate rings
Authors: Hambley TW , Hawkins CJ , Martin J , Palmer JA , Snow MR
Published: September 2010

An analysis of the 3JH,H coupling constants for the CH2CH2 segment in the chelate rings formed by
N-methylethane-1,2-diamine, and a crystal structure analysis of [Co(NH3)4{(±)-pn}] (S2O6)1.5,H2
(pn, propane-1,2-diamine) have shown that in cobalt(III) five-membered diamine chelate rings the
NCCN torsional angle is approximately 51°. For platinum(II) complexes of N-methylethane-1,2-
diamine, the 3JH,H technique yielded a value of 52.5° for the NCCN torsional angle. Problems
involved with the refinement of the structure prevented the determination of a reliable value of this
torsional angle in the crystal structure analysis of [Co(NH3),{(-)-dmbn}] (NO3)3,1.5H2O where
dmbn is 3,3-dimethylbutane-1,2-diamine. However, this analysis showed that (-)-dmbn has the
(R)-absolute configuration. The 3J H,H values for the CH2CH segment in complexes of dmbn show
that the NCCN torsional angle for the dmbn chelates in solution is significantly greater than for the
other diamines. The conformer populations for the N-methylethane-1,2-diamine complexes were
also determined by the 3JH,H technique. For the tetraamminecobalt(III) and tetracyanocobaltate(III)
complexes the mole fractions of the conformer with the methyl group equatorial were found to be
0.92 and 0.78, respectively. For the bipyridineplatinum(II) complex, one conformation was found
to be populated exclusively. This was assumed to be the axial conformer because of the unfavourable
interaction of the equatorial N-methyl group with the proton on C6 of the 2,2'-bipyridine group.
The Jpt, H values for an equatorial C-H proton in square-planar platinum(II) complexes of dmbn
show that the t-butyl group is restricted to the equatorial orientation even in this stereochemistry.
The conformational-energy minimization technique was applied to the two complexes studied by
crystal structure analysis.
Copper complexation by isatin β-thiosemicarbazones in aqueous solution
Authors: Stunzi H
Published: September 2010

The reactions in aqueous
solution between cupric ion and water-soluble derivatives of the antiviral drug
methisazone (1-methylisatin β-thiosemicarbazone,
mibt) have been investigated. Alkalimetric
titrations and n.m.r. experiments showed that 5-sulfonatoisatin β-thiosemicarbazone,
sibt (3), its 1-methyl derivative, msibt (4), and also p-sulfonatobenzaldehyde thiosemicarbazone, sbat
(5), reduce cupric ion and form copper(I) complexes. Stability constants were
obtained from measurements of pH and pCu+
on solutions of copper(II) nitrate and excess ligand (I = 0.15 M KNO3, at 37�). The pCu+
values were obtained with an ORION solid state copper electrode. At pH 6-7.5
and moderate excess of ligand, polymeric complexes with an approximate 1 : 1
copper(1)-to-ligand ratio are formed: CunLn
or CunLn+,H with n > 6. Monomeric
complexes CuL23- predominate at higher pH and in the
presence of a more than twentyfold excess of ligand.
The stability constants log β2 are 17.9 for sibt, 18.5 for
msibt and 19.8 for sbat. At physiological pH (7.4),
the order of stability is msibt > sibt & sbat,
with conditional stability constants log β2 = 16.2, 15.7 and
13.4, respectively. Comparison with penicillamine
shows that some in vivo complexation of copper(I) by methisazone
may be possible. On the other hand, a histidinato-copper(II)
complex is formed in the presence of histidine.
A synthesis of hydroxylated isoflavylium salts and their reduction products
Authors: Liepa AJ
Published: September 2010

Phloroglucinol reacts with arylmalondialdehydes in the presence of hydrochloric acid
to form 5,7-dihydroxyisoflavylium salts. Reduction of these salts can be
utilized to form isoflav-2-enes, isoflav-3-enes or isoflavans.
Reactions of copper(II) with ligands containing thioether donors
Authors: Braithwaite AC , Rickard CEF , Waters TN
Published: September 2010

Preparations of three
ligands containing thioether donor atoms are detailed
and their interactions with cupric ions discussed. The affinity of these sulfur
donors for copper(II) is small, and stable complexes can only be formed under
restricted solvent and anion conditions.
Depsidone synthesis. XXII. An alternative synthesis of gangaleoidin
Authors: Cullen LJ , Sargent MV
Published: September 2010

A new synthesis of the
lichen depsidone gangaleoidin (1) (methyl
2,4-dichloro-3-hydroxy-8-methoxy-1,6-dimethyl-11-oxo-11H-dibenzo[b,e][l,4]dioxepin-7-carboxylate) is described. It depends
on the oxidation of methyl 4-hydroxy-3-(4',6'-dihydroxy-2'-methylbenzoyl)-6-methoxy-2-methylbenzoate
(7)to methyl
6-hydroxy-4,6'-dimethyl-4'-methoxy-2',3-dioxo-2,3-dihydrospiro[benzofuran-2,1'-cyclohexa-3',5'-dienel-5'-carboxylate
(8), and the thermolysis of this compound to methyl
3-hydroxy-8-methoxy-1,6-dimethyl-11-oxo-11H-dibenzo[b,e][l,4]dioxepin-7-carboxy1ate
(2), which had been previously converted into gangaleoidin (1) by chlorination.
Five new C26 tetracyclic terpenes from a sponge (Lendenfeldia sp.)
Authors: Kazlauskas R , Murphy PT , Wells RJ
Published: September 2010

Five new scalarane sesterterpenes have been isolated from a Western
Australian sponge (Lendenfeldia
sp.). As with earlier reported examples of these compounds, several of these
metabolites of this sponge are extremely potent inhibitors of platelet aggregation.
Two diterpenes with new carbocyclic ring systems from an Australian collection of the brown alga Dictyota dichotoma
Authors: Blount JF , Dunlop RW , Erickson KL , Wells RJ
Published: September 2010

The dichloromethane extract
of the brown alga Dictyota dichotoma has
yielded a number of known diterpenes together with representatives of two
previously unreported carbocyclic diterpene
classes. The structure and absolute stereochemistry of the bicyclo[3,3,1]nonane derivative (6) was solved by single-crystal X-ray
analysis of a heavy-atom derivative and the gross structure of the dialdehyde (8) was inferred from spectral evidence.
C18 terpenoid metabolites of the brown alga Cystophora moniliformis
Authors: Ravi BN , Murphy PT , Lidgard RO , Warren RG , Wells RJ
Published: September 2010

Ten new terpenoid
compounds have been isolated from the brown alga Cystophora moniliformis. Their isolation
and structural elucidation, mainly on spectral evidence, is discussed, together
with data on four previously reported compounds.
Reactions of aryl diazonium salts and arylazo alkyl ethers. VI. A comparison of the available methods for the measurement of the rate of ionization of (Z)-arylazo alkyl ethers in alcoholic solvents
Authors: Broxton TJ , Mcleish MJ
Published: September 2010

Two previously reported
methods for the determination of the ionization rate of (Z)-arylazo alkyl ethers by using x-naphtholate ions as a trapping agent are compared. A new
method, which uses thiophenolate ions to trap the
free diazonium ions formed in this ionization, is
reported. This method is recommended in preference to the earlier methods
because it includes a correction for the effect of the ionic strength of the
solution on the rate of ionization. Rates measured by the thiophenolate
method are consequently lower than those measured by either of the two previous
methods. The advantages and disadvantages of the new method are discussed.
The
magnitude of salt effects and substituent effects on the ionization of (Z)- and (E)-arylazo alkyl ethers are compared.
Phosphorus-31 and cadmium-113 N.M.R. studies of cadmium(II) complexes with some tertiary phosphines
Authors: Dakternieks D
Published: September 2010

Phosphorus-31 and
cadmium-113 n.m.r, techniques have been used to investigate the formation, in
solution, of some cadmium(I) complexes CdA2(phos)n
[where A = ClO4-, NO3-, CH3COO-, Cl-, Br-, I-
and phos = PBu3, P(C6H11)3]. The
effective coordination number of the cadmium atom is dependent on the nature of
the phosphine and of the anion A and ranges from two to five in dichloromethane
solution.
Heterocyclic ambident nucleophiles. IV. The alkylation of metal salts of adenine
Authors: Rasmussen M , Hope JM
Published: September 2010

The N3 : N7 : N9 alkylation
patterns for reactions of the lithium, sodium, and potassium salts of adenine
with various alkylating agents in dimethyl sulfoxide were determined by 1H
n.m.r. spectroscopy. Only for the Li+ salt was any significant
effect of ionic association noticed. Of the alkylating agents used, only
chloromethyl pivalate gave a concentration dependent alkylation pattern. The
latter effect was most pronounced with the heterogeneous alkylation conditions
of anhydrous Na2CO3/HCONMe2, adenine, and
chloromethyl pivalate; here, increasing concentrations changed the main
reaction from N7- to N9-alkylation. Solvent effects on the alkylation patterns
were also studied. Within the common dipolar aprotic solvent group, (Me2N)3PO,
HCONMe2 and Me2SO, effects were small; in protic
solvents, particularly formamide, enhanced N3-alkylation was observed.
Constituents of Endiandra species. III. 4-[(E,E)-5'-Phenylpenta-2',4'-dien-1'-yl]tetra-cyclo[5,4,0,02,5,03,9]undec-10-ene-8-carboxylic acid from Endiandra introrsa (Lauraceae)
Authors: Bandaranayake WM , Banfield JE , Black DSC , Fallon GD , Gatehouse BM
Published: September 2010

The structure (5) is proposed for the title compound
on the basis of chemical and spectroscopic evidence and on the X-ray crystal
structure of the derivative 4-{(Y-methyl-1'',3''-dioxo-7''-phenyl-
1'',3'',3'',4'',7'',7a''-hexahydroisoindol-4''-yl)methyl}tetracyclo [5,4,0,02,5,O3,9] undec-10-ene-8-carboxylic acid (9c).
Interactions of iron(II) and iron(III) with gallic acid and its homologues: a potentiometric and spectrophotometric study
Authors: Powell HKJ , Taylor MC
Published: September 2010

The reactions between
iron(III) and the phenols gallic acid, catechol, protocatechuic acid and
pyrogallol have been studied in aqueous solution at 25�C (I 0.10 M KCl). From spectrophotometric and pH titration data it was
established that (i) complexes with 1 : 1, 1 : 2 and 1 : 3 (M : L) stoichiometry
are formed in oxygenated solution, (ii) the redox reaction given at low pH by
these ligands
Fe3+ + �phenol → Fe2+ + �quinone + H+
is not reversed by
complexing of Fe3+ at higher pH, and (iii) the percentage
composition of iron(II) and iron(III) in solutions of these ligands is a
function of ER (ligand), the pH and age of solutions and the partial
pressure of dissolved oxygen.
The reaction of N-dichloromethylene-N,N-dimethylammonium chloride (Viehe's salt) with methyl 4,6-O-benzylidene-α-D-glucoside. An alternative synthesis of methyl 4,6-O-benzylidene-α-D-alloside
Authors: Copeland C , Stick RV
Published: September 2010

The reaction of methyl 4,6-O-benzylidene-α-D-glucoside
with N-dichloromethylene-N,N-dimethyl-ammonium
chloride (Viehe's salt) in the presence of a base gives a mixture of carbamates (with triethylamine) or the 2,3-carbonate mainly
(with pyridine). The treatment of this carbonate with various primary and
secondary amines, again to give mixtures of carbamates,
and an efficient synthesis of methyl 4,6-O-benzylidene-α-D-alloside from
one of the gluco carbamates, are reported.
The influence of stereochemistry on the dehydration of 5-Acetoxy-8a-methyldecahydronaphthalen-4a-ols
Authors: Coxon JM , Gibson JR
Published: September 2010

The dehydration of (4α,5α,8aβ)-
and (4aα,5α,8aα)-5-acetoxy-8a-methyldecahydronaphthalen-4a-ol
with SOCl2/pyridine and H2SO4/Ac2O/HOAc
is reported. For both substrates methyl migration does not compete with
1,2-elimination but for the (4aα,5α,8aα)-alcohol, spiran
formation, resulting from migration of Cl to C4a, is observed on reaction with
H2SO4/Ac2O/HOAc. The influence of the relative
stereochemistry at C4a, C5 and C8a on the course of reactions is discussed.
The preparation and characterization of mer-Bis[di(3-aminopropyl)amine]cobalt(III) perchlorate, and the crystal structure of its hydrolysis product Bis[di(3-aminopropyl)amine]tri-μ-hydroxo-dicobat(III) perchlorate
Authors: Searle GH , Hambley TW
Published: September 2010

mer-[Co(dpt)2] Cl3 [dpt = di(3-aminopropyl)amine] has
been obtained from substitution or oxidation reactions in non-aqueous solvents,
and transformed to the perchlorate salt. The
different form of the 13C n.m.r. spectrum to that of mer-[Co(dien)2]3+ (dien
= diethylenetriamine), and variation of the spectrum
with basicity, is taken to indicate high conformational mobility of the coupled
six-membered chelate rings
of the mer
structure. Slow hydrolysis occurs in neutral water (but is prevented by acid),
and the hydrolysis product has been isolated. The s-fac and u-fac [Co(dpt)2]3+
isomers have not been detected chromatographically in the preparations, and any
isomerization of the mer
isomer is masked by the hydrolysis. X-ray crystallographic analysis shows that
the isolated hydrolysis product is the racemic
geometric isomer (C2 symmetry) of [(dpt)Co(OH)3Co(dpt)] (ClO4)3. Each facially
coordinated dpt adopts the ring conformations chair,
irregular-boat. The crystals are monoclinic, space group P21/n, with
a 15.053(5), b 13.964(2), c 14.010(3) �,
β 109.90(2)�. The structure was refined by blocked-matrix least-squares
techniques to an R factor (3190F) of
0.032.
Cyclopentadienyl-ruthenium and -osmium chemistry. XIX. Some complexes containing η2-olefin, η2-allene and η2-alkyne ligands
Authors: Bruce MI , Hambley TW , Rodgers JR , Snow MR , Wong FS
Published: September 2010

Reactions between RuCl(Pme3)2(η-C5H5)
and unsaturated hydrocarbons in the presence of NH4PF6 have
given [Ru(η2-un)(PMe3)2(η-C5H5)]
PF6[un = C2H4, (E)-CH(CN)=CH(CN),CH2=CHCH=CH2,
CH2=C=CH2, CH2=C=CMe2, C2Ph2,
PhC2C2Ph, PhC2CO2Et, C2(CO2Me)2
and C2(CF3)2]. The molecular structures of the
buta-1,3-diene (3) and allene (4) complexes have been
determined. In both compounds, the unsaturated hydrocarbon is bonded to
ruthenium in an asymmetric η2 mode: Ru-C
2.185, 2.242(5) [for (3)], 2.084, 2.172(6) [for (4)l; coordinated C=C 1.386(8),
1.394(8) A, respectively. The allene skeleton is bent
by 35� at the central carbon. Crystal data: (3) monoclinic, P21/n, a 17.343(2), b 13.692(4), c 17.997(3) �,
β 94.91(1)�, Z 8; (4) orthorhombic, Pca21, a 18.999(3), b 9.253(3), c 23.016(6) �, Z 8. The structures were
refined to residuals of R 0.026, R, 0.028 for 4076 data with 1 > 2.5σ(I) [for (3)], and R 0.022, Rw 0.024 for 3054 data [for (4)].
Crystal structure and absolute configuration of (+)-scandine hydrobromide
Authors: Cannon JR , Croft KD , Matsuki Y , Patrick VA , Toia RF , White AH
Published: September 2010

The major alkaloid of a
Fijian Melodinus
sp. (family Apocynaceae) has been identified as (+)-scandine (1). The crystal structure and absolute
configuration of the acetone solvate of (+)-scandine hydrobromide have been determined by X-ray diffraction; diffractometer data at 295 K were refined by block diagonal
least squares to a residual of 0.037 (2657 'observed' reflections). Crystals of
the hydrobromide are monoclinic, P21, a 9.496(3), b 14.561(5), c 9.339(3) �,
β 115.39(2)�, Z 2. Although the cations of
(+)-scandine hydrobromide
and (+)-N-methylmeloscine
bromide have the same skeleton and the same absolute configuration, they have
different conformations; this appears to be due to the steric effect of the N-methyl group in the latter cation.
Chemistry of the Podocarpaceae. LXIII. Ring-C oxidation of totarol
Authors: Cambie RC , Hayward RC , Palmer BD
Published: September 2010

Methods
for the conversion of totarol (1) into the catechol
derivative (2) are described. Oxidative cleavage of the derived methyl ether
(13) by ozonolysis affords a high-yielding route to a
compound (34) with potential as a nagilactone precursor.
Terpenoid chemistry. XXV. The absolute configuration of ( - )-ngaione, ( - )-epingaione and related substances
Authors: Russell CA , Sutherland MD
Published: September 2010

The
absolute configuration of (-)-ngaione has been confirmed as (2'S,5'R)-4-methyl-1-(5'-methyl-2',3',4',5'-tetrahydro[2',3''-bifuran]-5'-yl)pentan-2-one
as was proposed by Hegarty, Kelly, Park and
Sutherland
in 1970, by converting it into (–)-ngaiane, (2S,5S)-5-methyl-5-(4''-methylpentyl)-2,3,4,5-tetrahydro[2,3'-bifuran], which
is shown to resist ring opening by nucleophiles. Further confirmation
was
obtained by the ozonolysis of (–)-ngaiane to (–)-(4R)-4,8-dimethylnonan-4-olide comparable in
molecular rotation with (–)-(4S)-4-methylhexan-4-olide which has been
correlated with (–)-(R)-linalool. Wolff-Kishner reduction of the hydrazone or
semicarbazone of (–)-ngaione yields mainly an E,Z(1S,4ξ)-1-(furan-3'-yl)-4,8-dimethylnon-5-en-1-ol with
some ngaiane. Being (+)-ngaione, ipomeamarone does not have the absolute
configuration assigned by Kubota, Nakajima and Matsuura in 1964. The name
ipomeamarone is redundant, implies an incorrect stereochemistry and should be
abandoned.
Synthesis of (2S)-2-Propylthietan
Authors: Crump DR
Published: September 2010

(2S)-2-Propylthietan
(10) has been synthesized to determine the enantiomer
composition of the 2-propylthietan isolated from the anal gland secretion of
the stoat (Mustela
erminea).
Substituent effects on the isomer ratios in the rearrangement of some 2- and 4-nitraminopyridines
Authors: Deady LW , Korytsky OL , Rowe JE
Published: September 2010

The preparation, and
rearrangement in 92% sulfuric acid, of 4-X-2-nitramino- (1), 2-X-4-nitramino-(2),
and 6-X-2-nitramino-pyridines (3) is reported (X = H, Me, MeO, Br, Cl, CO2H).
The product isomer ratios can be explained by differential electronic stabilization
of the appropriate a complexes for aromatic nitration and steric effects seem
relatively unimportant. Deuteration [3-D in series (1), X = Me] had no effect
on the product distribution.
Synthesis of some derivatives of 2,5-Anhydro-D-mannitol
Authors: Guthrie RD , Jenkins ID , Watters JJ , Wright MW , Yamasaki R
Published: September 2010

The
synthesis of 2,5:3,4-dianhydro-D-allitol
and of a variety of derivatives (sulfonyloxy,
deoxy, azido, iodo, etc.) of 2,5-anhydro-D-mannitol
is described.
The role of binuclear rhodium complexes as possible intermediates in the formation of cyclopentadienone-rhodium complexes. Reactions between (η-C5H5),Rh2(CO)(CF3C2CF3) and symmetrically disubstituted alkynes
Authors: Corrigan PA , Dickson RS , Johnson SH , Pain GN , Yeoh M
Published: September 2010

A stepwise pathway for the formation of cyclopentadienone complexes (η-C5H5)Rh{C4R4CO} from
(#-C5H5)Rh(CO)2 and RC≡CR has been elucidated. When solutions of (η-C5H5)Rh(CO)2 are
heated, there is loss of CO and (η-C5H5),Rh2(CO)3 is formed. This reacts with alkynes to give
binuclear complexes such as (η-C5H5),Rh2(CO)2(CF3C2CF3) gives (ηC5H5)2Rh2(CO)(ButC2But).
Removal of CO from (η-C5H5)2Rh2(CO)2(CF3C2CF3) gives (η-C5H5)2Rh2(CO)(CF3C2CF3) and
this monocarbonyl complex reacts with more alkyne, R'C≡CR', to form the bis-alkyne complex
(η-C5H5)2Rh2(CO)(CF3C2CF3)(R'C2R')(R' = SiMe3) and then the pentadienone complex
(η-C5H5)2Rh2{C4(CF3)2R'2CO} (R' = =Me, Me3Si, CF3). In some instances (R' = Ph, But, CO2Me),
this reaction gives equimolar amounts of the metallodiene complex (η-C5H5)2Rh2{C4{CF3)2R'2}
plus the dicarbonyl complex (η-C5H,)2Rh2(CO)2(CF3C2CF3). The binuclear pentadienone
complexes (η-C5H5),Rh2{C4R2R'2CO) (R = CF, and R' = Me; or R = R' = Et) can be converted
into mononuclear cyclopentadienone complexes (η-C5H5)Rh{C4R2R'2CO} by heating in the
presence of CO or alkyne, or both.
Crystal structures of Dimeric O-ethylxanthato-quinolin-8-olato-lead(II) and of tetraethylammonium Tris-(O-ethylxanthato)plumbate(II)
Authors: Hardin SG , Healy PC , Mumme WG , White AH , Winter G
Published: September 2010

The crystal structures of
the title compounds have been carried out by single-crystal X-ray diffraction
methods at 295 K. For (1), [(EtOCS2)Pb(C9H6NO)2Pb(S2COEt)],
crystals are triclinic, P1, a 11.600(6), b 8.9739, c 6.863(4) �, α
96.79(5), β 90.19(5), γ 101.54(4)�, with one dimer in the cell. R was
0.038 for 3109 'observed' reflections. The lead atom is coordinated by two
sulfur atoms from the xanthate ligand [Pb-S 2.705(3), 3.173(3) �], the quinolin-8-olato nitrogen
atom [Pb-N 2.479(6) �] and the oxygen atom which
bridges two centrosymmetrically related lead atoms [Pb-O 2.296(5), 2.548(4) �]. For (2), (Et4N) [Pb(S2COEt)3], crystals are
monoclinic, P21/c, a
10.827(3), b 18.889(6), c 14.292(5) �, β 111.05(2)�, Z 4. R
was 0.050 for 3657 'observed' reflections. The lead atom is surrounded by the
six sulfur atoms [Pb-S 2.754(4)-3.126(3) �], with
close approaches from the two sulfur atoms of one of the ligands of a centrosymmetrically related anion [Pb..
.S 3.545(4), 3.555(4) �], in a similar manner to that observed in the 'isoelectronic' tris(N,N-diethyldithiocarbamato)bismuth(III) complex.
Alkyne formation in the reaction of α-bromo ketones with arylsulfonylhydrazines
Authors: Bryant MW , Smith RAJ , Wong L
Published: September 2010

Alkynes can be produced by
treating some α-bromo ketones with arylsulfonylhydrazines. The reaction is
acid-catalysed and mesitylsulfonylhydrazine was the most efficient hydrazine
reagent examined. The mechanism of the reaction has not been elucidated although
it is shown not to proceed via an α-bromo mesitylsulfonylhydrazone.
The reaction of piperazine-2,5-dione with 2-formylbenzoic acid.
Authors: Baron ML , Rae ID , Simmonds PM
Published: September 2010

Reaction
of piperazine-2,5-dione with 2-formylbenzoic acid in the presence of
triethylamine gives three products: 1-(3'-oxo-1',3'-dihydroisobenzofuran-1'-yl)piperazine-2,5-dione, its
1,4-bis analogue
which
had previously been identified as the 3,6-compound, and 2,2'-[3,6-dioxopiperazine-2,5-diylidenebis(methylidyne)]bis(benzoic acid).
The latter compound is shown by 1H and 13C n.m.r,
spectroscopy
to
be the Z,Z isomer.
Organoselenium chemistry. Synthesis of selenetan-3-ol, 1-bromo-3-selenocyanatopropan-2-ol and 2-benzylseleno-substituted fumaricand succinic acids
Authors: Arnold AP , Canty AJ
Published: September 2010

Approaches to the synthesis of diselenols have led to isolation of several new organoselenium
compounds. Removal of mercury, as HgS, from [1,3-diselenylpropan-2-olato(2–)-Se,Sel]-mercury(II)
results in decomposition of the organoselenium fragment to selenetan-3-ol, 1,3-Dibromopropan-2-ol
reacts with KSeCN to form 1-bromo-3-selenocyanatopropan-2-ol; the selenoethers 2-(benzyl-
se1eno)fumaric acid [(Z)-PhCH2SeC(CO2H)=CHCO2H] and 2-(benzylseleno)succinic acid
[PhCH2SeCH(CO2H)CH2CO2H] are formed by base-catalysed reaction of phenylmethaneselenol
with acetylenedicarboxylic acid and maleic acid, respectively. The conformations adopted by
PhCH2XCH(CO2H)CH2CO2H (X = S, Se) in acetone have been determined by 1H n.m.r.
spectroscopy.
A 'Classical' approach to the synthesis of perloline
Authors: Kasum B , Prager RH
Published: September 2010

An approach to the
synthesis of perloline by the reaction of (2-bromophenyl)(3',4'-dimethoxy-
phenyl)amine with a suitably 4-substituted 2-oxo-1,2-dihydropyridine-3-carboxylic
acid was unsuccessful due to the inability to form the amide bond. The
diphenylamine was efficiently synthesized from the nitrone of
dimethoxybenzylidene-2-bromoaniline via the oxaziridine,
the thermal rearrangement of which was investigated. Conjugate additions of a
diphenylamine dianion to unsaturated esters are
reported.
Liquid junction potentials across the interface between the aqueous saturated calomel electrode and some nonaqueous solvents, based on the tatb assumption
Authors: Datta J , Bhattacharya S , Kundu KK
Published: September 2010

The liquid junction
potentials (Ej) across aqueous saturated KCl/nonaqueous solvent junctions have been determined
within the framework of the tetraphenylarsonium tetraphenylborate (tatb) extra-
thermodynamic assumption. The nonaqueous solvents
comprise methanol, ethylene glycol, acetonitrile,
propylene carbonate, dimethylformamide and dimethyl sulfoxide. The Ej
values obtained are fairly small (below 40 mV) in the case of protic solvents and fairly large (within 100-200 mV) in the
case of dipolar aprotic solvents, as expected if
primarily guided by solvent-solvent interactions across the liquid junctions.
The results allow the aqueous saturated calomel electrode to be used to relate
electrode potentials in different solvents.