bluuebunny/crossref_metadata_2025 huggingface dataset:
N.M.R. studies of some chromium(III) dithiocarbamate complexes
Authors: Golding RM , Healy PC , Colombera P , White AH
Published: September 2010

The temperature dependence
of the proton N.M.R. spectra of some simple tris(N,N-disubstituted dithiocarbamato)chromium(111)
derivatives, [Cr(S2CNR2)3], has been studied
in deuterochloroform solution over the range ? 60� to + 60�C. In these spectra,
which are very broad, the N-CHn protons in certain cases exhibit a double
peak unlike the iron(111) or manganese(111) complexes-probably a consequence of
high energy barriers between the Δ and Δ enantiomers, the broadness
of the spectra being ascribed to the lack of an appropriate relaxation
mechanism. The spectra of a number of further iron(111) and manganese(111)
derivatives are reported and the hyperfine coupling constants in the three series
of complexes compared.
Chemistry of pyrrolic compounds. XXVIII. The synthesis of acrylic acid porphyrins: Porphyrin mass spectra
Authors: Clezy PS , Lim Cl , Shannon JS
Published: September 2010

The synthesis and
properties of a porphyrin substituted with acrylic ester side chains is
described. Some aspects of the fragmentation of porphyrins in the doubly
charged region of their mass spectra are discussed.
Acridone studies. XIII. The nature of hexabromoacridone
Authors: Prager RH
Published: September 2010

Acheson's
?hexabromoacridone?1 is shown to be 1,2,3,4,5,7-hexabromo-9- acridone
by a combination of N.M.R. spectroscopy and synthesis from specifically
tritiated 9-acridones. In boiling piperidine, the bromines at C 1 and C 3 are
replaced.
Bis(η-cyclopentadienyl)vanadium(IV) dithiochelates
Authors: Casey AT , Thackeray JR
Published: September 2010

Complexes have been
isolated between the bis(q-cyclopentadienyl)vanadium(IV)
moiety and the maleonitriledithiolate, N- cyanodithiocarbimate, O-ethyl
thioacetothioacetate, dithiobiuret and dimethyldithioarsinate anions. The
results of conductance and magnetic measurements and of infrared, electronic
and e.s.r. spectra have been interpreted in terms of the expected structure of
the complexes.
Structure of norerythrostachaldine, a cytotoxic alkaloid from Erythrophleum chlorostachys (Leguminosae)
Authors: Loder JW , Nearn RH
Published: September 2010

Norerythrostachaldine (1) and its naturally occurring 3β-acetate (2)
are highly cytotoxic aldehydic bases considered to be 19- oxonorcassaidine and
its 3β-acetate. The carbon skeleton, stereochemistry and position of
oxygen substituents were established by lithium aluminium hydride reduction of
(1) to give the tetrol (3) which was identical with a sample prepared from norerythrostachamine (4).
Studies of organophosphorochloridates. The preparation of some bisaryl phosphorochloridates derived from o-biphenol and o-cyclohexylphenol
Authors: Cremlyn RJW , Kishore N
Published: September 2010

Anhydrous aluminium
chloride was discovered to be the most active catalyst for the phosphorylation
of phenols, and was specially useful in the synthesis of bisaryl
phosphorochloridates. The aryl phosphorodichloridate was prepared by reaction
of the phenol with phosphorus oxychloride using the less reactive potassium
chloride catalyst, followed by treatment of the resultant phosphorochloridate
with another phenol in the presence of aluminium chloride catalyst. The
phosphorochloridates were characterized by conversion into N- substituted
phosphoramidates and phosphorohydrazides.
A novel arsenic complex of zirconium(III)
Authors: Kepert DL , Trigwell KR
Published: September 2010

The prolonged reaction of
zirconium tetrachloride with 1,2- bis(dimethylarsino)-3,3,4,4-tetrafluoro-cyclobutene
(tfars) in acetonitrile forms [ZrCl3(tfars)] MeCN. This compound
appears to be the first magnetically dilute complex of zirconium(III).
Post-Infectional Compounds From the French Bean Phaseolus vulgaris; Isolation and Identification of Genistein and 2',4',5,7-Tetrahydroxyisoflavone
Authors: Biggs R
Published: September 2010

The isolation and
identification of two isoflavones from fungal- infected pods of Phaseolus vulgaris L. is
described. One, genistein, is known to occur in other legumes. On the basis of
ultraviolet and p.m.r. spectroscopy and of mass
spectra, the second compound was tentatively identified as 2?,4?,5,7-tetrahydroxyisoflavone.
The reaction of tertiary alcohols with phosphorus pentachloride
Authors: Carman RM , Shaw IM
Published: September 2010

Reaction with phosphorus
pentachloride under extremely mild conditions is a method of choice for the
synthesis of tertiary chlorides from tertiary alcohols with retention of
configuration.
The preparation and mass spectrometric studies of carboxy-substituted oxazoles derived from (S)-serine
Authors: O'Conner MJ , Smith JF , Teo S
Published: September 2010

The copper(11) complex
formed by the reaction of bis((S)-serinato)copper(11) and formaldehyde under
alkaline conditions was treated with sodium borohydride to give the sodium salt
of dihydro-1 H,3H,5H-
oxazolo[3,4-c]oxazole-7a-carboxylic acid. This reaction does not cause
appreciable cleavage of the oxazole ring system. The methyl and ethyl esters of
the acid were prepared and characterized by gas chromatography/mass
spectrometry (g.c.-ms.). Breakdown patterns involving loss of formaldehyde are
described.
The kinetics of the decarboxylation of β-resorcylic acid in catechol
Authors: Haleem MA , Hakeem MA
Published: September 2010

Kinetic data are reported
for the decarboxylation of β-resorcylic acid in
resorcinol and catechol for the first time. The reaction is first order. The
observation supports the view that the decomposition proceeds through an
intermediate complex mechanism. The parameters of the absolute reaction rate
equation are calculated.
The determination of the surface area of silica by laser Raman spectroscopy
Authors: Cooney RP , Tam NT
Published: September 2010

Changes in the Raman
spectrum of pyridine on a silica surface with increasing surface coverage may
be used to determine the monolayer capacity. The method, which is independent
of the BET method, produces a result which is in quantitative agreement with the
BET result.
Electron-transfer reactions in non-aqueous media. III. Reduction of CoF(NH3)52+, CoCl(NH3)52+ and CoBr(NH3)52+ by iron(II) in N,N-dimethylformamide
Authors: Matthews BA , Turner JV , Watts DW
Published: September 2010

The reduction of the
cobalt(111) octahedral complexes CoF(NH3)52+,
CoCl(NH3)52+ and CoBr(NH3)52+
by iron(11) in HCONMe2 proceeds through a mechanism involving
reversible formation of a halide bridged binuclear intermediate prior to
electron transfer and decomposition of the intermediate to products. Values of
the activation parameters for reduction and the equilibrium constants for
formation of the bridged intermediate are consistent with a tetrahedral
stereochemistry for the iron(11) atom in the bridged intermediate for the
chloro and bromo systems. However, for the fluoro
system these values are consistent with the iron(11) atom maintaining
octahedral coordination. These results are compared to those obtained in Me2S0.1,2
The glutarimide antibiotic 9-methylstreptimidone: Structure, biogenesis and biological activity
Authors: Allen MS , Becker AM , Rickards RW
Published: September 2010

The antibiotic responsible
for the high antiyeast and antifungal activity of a streptomycete fermentation
is shown to be the 9-methyl derivative (1) of streptimidone (2). The conjugated
diene system in (1) is assigned the 6E,8Z stereochemistry. Evidence is
presented for the biogenetic origin of the 9-methyl group in this streptimidone
homologue, and its antifungal activity is compared with that of streptimidone
and other fungicides.
The Lewis-acidity of square-planar nickel(II) complexes. I. A kinetic and thermodynamic study of the reaction of Bis(O,O-diethyl phosphorodithioato-S,S'-)nickel(II) with bidentate nitrogen donors
Authors: Grant MW , Magee RJ
Published: September 2010

The kinetics of the
addition reaction between bis(O,O-diethyl phosphorodithioato-S,S'-)nicke1(11)
and a series of bidentate nitrogen ligands has been examined by stopped-flow
techniques. The reactions are first order in ligand and nickel complex with kf,
the second-order rate constant, in the range from 103 to 106
1. mol-1 s-1 at 25�C in benzene. Solvent effects on the
reaction with 2,2'-bipyridyl are minor. The variation in kf with
ligand is discussed in terms of the steric requirements of the ligands, the
bulkiest ligand, 2,9-dimethyl-1,l0-phenanthroline, reacting most slowly. For
the ligands 1,l0-phenanthroline and 2,2'-bipyridyl in the more polar solvents,
successive displacement of the thiophosphate ligands follows the initial
addition step.
P.M.R. spectra of heteroaromatic molecules containing bridgehead nitrogen atoms. III. Pyrrolo[2,1-c][1,2,4]benzotriazine
Authors: Heffernan ML , Irvine GM
Published: September 2010

The detailed assignment and
analysis of the p.m.r. spectra of solutions of pyrrolo[2,1-c][1,2,4]benzotriazine
in dimethyl sulphoxide at 80� and 100�, and in acetic
acid at 60�, was carried out. The presence and approximate magnitudes of
several inter-ring long-range coupling constants were deduced by comparison of
the experimental and theoretically calculated spectra. Spin-tickling
experiments were used to determine the relative sign combinations of the
intra-ring coupling constants of the protons 1-3 and 6-9 in the particularly favourable case of the acetic acid solution of pyrrolo[2,1-c][1,2,4]benzotriazine.
All coupling constants were found to have the same sign, presumably positive.
Photochemistry of 2,2'-dinitrodiphenylmethanes: Irradiations in neutral, acidic and alkaline media
Authors: Joshua CP , Ramdas PK
Published: September 2010

Photolysis of
2,2'-dinitrodiphenylmethane (1) in isopropyl alcohol affords dibenzo[c,f][l,2]diazepin-11-one
5-oxide (7) as the major product. Dibenzo[c,f][l,2]diazepin-11-one 5,6-dioxide (6), acridone (8) and 2,2'-dinitrobenzophenone (9) are also
formed in the reaction. Irradiation of (1) in ethanolic sulphuric
acid on the other hand yields 3-(2'-nitropheny1)-2,l-benzisoxazole (11) as the
major product; small amounts of (7), (8) and (9) are also isolated. Photoconversion of (1) in triethylamine and alcoholic
triethylamine proceeds very slowly and compounds (7), (8) and (9) only are
isolated from the photolysed solution. Some aspects of the mechanism are
discussed.
E2 reactions of menthyl and neoisomenthyl Toluene-p-sulphonates
Authors: Beckwith ALJ , Phillipou G
Published: September 2010

The reaction of menthyl toluene-p-sulphonate (7)
with potassium t-butoxide in benzene-dimethyl sulphoxide proceeds regiospecifically
to afford trans-p-menth-2-ene (1).
Mixtures of olefins are obtained when sodium ethoxide
in ethanol, potassium t-butoxide in t-butyl alcohol
or tetrabutylammonium bromide in acetone are used. Neoisomenthyl toluene-p-sulphonate
(9), prepared by a stereospecific route from piperitone,
affords mixtures of cis-p-menth-2-ene (2) and p-menth-3-ene(3) when treated
with strong bases. The results are consistent with the concept of variable E2 transition states.
Oxygenation of a cobalt(II)-dioxime complex
Authors: Kee T , Powell HKJ
Published: September 2010

The ligand
4,4,9,9-tetramethyl-5,8-diazadodecane-2,dione dioxime (LH2) forms
cobalt(11) complexes [Co(LH)(H2O)2]+ and
[Co(LH)(H2O)OH]; the stabilities of these complexes have been determined
in aqueous solution at 25�C (I = 0.10 M NaCl). The hydroxo complex [Co(LH)(H2O)-OH]
reacts with dioxygen to give the non-labile oxygen adduct [(H0)(HL)CoO2Co(LH)
(OH)] in aqueous solution: this reaction has been followed by polarographic
oxygen sensor.
Regioselective and regiospecific Di-π-methane rearrangements. Photoisomerization of 9-substituted 9,10-Dihydro-9,10-ethenoanthracenes
Authors: Paddick RG , Richards KE , Wright GJ
Published: September 2010

The di-p-methane photoisomerization
of a series of 9-substituted dimethyl 9,10-dihydro-9,10-
ethenoanthracene-ll,12-dicarboxylates has been investigated. The bromo compound
(13) rearranges regiospecifically to give 4b-bromo-4b,8b,8c,8d-tetrahydrodibenzo[a,f]cyclopropa[cd] pentalene-8c,8d-
dicarboxylate (19) whereas the amine (16) rearranges regiospecifically via the 8b-amino compound which further
rearranges via an imine to give the keto diester (12). Rearrangement of the acetamido compound (17) gave the 4b-isomer (22) (60%), the
keto diester (12) (25 %) and a cyclooctatetraene (28)
(15%), while the methoxy and ethoxy compounds (14)
and (15) gave the 4b-isomers (20) and (21) (85%) and the keto diester (11)
derived from the 8b-isomer. Both the 4b- and 8b-isomers (23) and (27), (65 %)
and (35 %), were isolated when the methyl ethenoanthracene
(18) was photolysed. The rearrangement of these compounds is explained in terms
of the electronegativity and hydrogen bonding ability
of the 9-substituent. The more electronegative the substituent the more the
4b-isomer is favoured while hydrogen bonding favours
the 8b-isomer. Photoisomerization of the monoesters
(29), (31) and (32) confirms the importance of odd-electron stabilization by an
adjacent methoxy- carbonyl group in determining the direction of the
rearrangement.
Oxidation of emodin anthrone and stereochemistry of emodin bianthrone
Authors: Cameron DW , Edmonds JS , Raverty WD
Published: September 2010

Synthetic emodin bianthrone
is separated into meso-
and (�)-diastereomers which are identified by means
of an asymmetric p.m.r. shift reagent. They behave
differently on mild oxidation. Both give protohypericin accompanied by an
anthraquinone fraction but, whereas the major anthraquinone from the meso is emodin,
the (k) gives chiefly the bianthraquinonyl, skyrin.
This difference is accounted for in terms of the geometry of oxidative
coupling. Oxidation of emodin anthrone in alkaline
dimethyl sulphoxide gives a l,4-anthraquinone as
major product. The scope of this novel oxidation has been extended to other
anthrones and it has been utilized in the controlled synthesis of purpurin derivatives. It may involve anthrslnol
tautomers as intermediates.
The application of ketimine derivatives of amino acids to peptide synthesis
Authors: Hope AP , Halpern B
Published: September 2010

N-(2-Hydroxyarylmethy1ene)amino
acids have been coupled with amino acid esters to form sterically pure
N-protected dipeptide esters. The protecting group can be removed by means of
80% acetic acid under conditions which leaves the t-butyloxycarbonyl protecting
group intact. Biologically active peptides which are C-terminal partial
sequences of substance P were prepared and were shown to have the expected
vasodilator, spasmogenic and venoconstrictor
properties.
Methyleneketenes and methylenecarbenes. VI. Pyrolytic generation of acyloxycarbenes and their rearrangement to 1,2-diketones
Authors: Brown RFC , Eastwood FW , Lim ST , McMullen GL
Published: September 2010

Thermal fragmentation of
5-acyloxy-1,3-dioxan-4,6-diones (4) or thermal α-elimination of benzoic acid
from the benzoyloxylactones (14) and (15) leads to
1,2-diketones in high yield. It is proposed that these 1,2-diketones are
products of the rearrangement of transient intermediates which are formulated
as acyloxycarbenes.
The N-alkylation of some barbiturates and other acidic drugs
Authors: Dilli S , Pillai DN
Published: September 2010

The synthesis of a number
of new N,N'-dialkyl barbituric acids
is reported. The compounds are ethyl hexobarbital, the diethyl derivatives of
secobarbital and cyclobarbital, the chloroethyl derivatives ofmephobarbital and
hexobarbital, and the bis(chloroethy1) derivatives of barbital, cyclobarbital,
secobarbital, butobarbital and secbutobarbital.In addition, several new N-alkylated derivatives of some common
anticonvulsant drugs are included. These are ethyl glutethimide, the
chloroethyl derivatives of ethosuximide, glutethimide, peganone, mephenytoin
and diphenylhydantoin. Infrared, N.M.R., mass spectral and gas chromatographic retention
data are given.
Photochemical syntheses. X. Photodimers of derivatives of naphthalenecarboxylic acids
Authors: Teitei T , Wells D , Sasse WHF
Published: September 2010

Photodimers that are derivatives of the ring system (3) have
been obtained from six out of 28 mono- and di-substituted
naphthalenes examined. The only dimers obtained are
head-to-tail isomers that are formed by bonding between the substituted rings
of two molecules of the naphthalene derivative. 2-Naphthoic acid anhydride
gives the intramolecnlar adduct (3g). The dimers (3h)
and (3i) rearrange below 100� to give (4h) and (4i), respectively. Irradiation
of methyl 3-methoxy-2-naphthoate in the presence of pyrene
gives a mixture of (3i) and (6).
Thio derivatives of β-diketones and their metal chelates. XXIV. Dipole moments and mass spectra of chromium(III) chelates of some monothio-β-diketones
Authors: Livingstone SE , Oluka JE
Published: September 2010

Chromium(111) chelates of
four monothio-β-diketones, RC(SH)=CHCOR? (R = R'
= Ph; R = Ph, 2-thienyl, β-naphthyl, R' = CF3),
have been prepared by the reaction of chromium(111) chloride hexahydrate with the monothio-β-diketone
in alcohol in the presence of urea. The dipole moments of the chromium chelates
were determined by static polarization measurements in benzene solution and
indicate a facial-octahedral configuration. The mass spectrum of CrL3
(L = PhC(S)=CHCOPh) shows
no metal-containing peaks but exhibits metal-free peaks due to the ions 2L-H2S,
2L - H2S- Ph, 2L- H2S - PhCO
and 2L- H2S - PhCO - Ph. The mass spectra
of the other three chromium chelates display a considerable number of peaks due
to metal-containing ions, including M and M - L. The difference in these
spectra from those of their cobalt(111), rhodium(111), iron(111) and ruthenium(111)
analogues is discussed.
Sulphide and selenide nitrosyl complexes of ruthenium
Authors: Fergusson JE , Page CT
Published: September 2010

Complexes of the type
[Ru(NO)X3L2] have been isolated where X = Cl, Br and L = R2S and PhRS
(R = Me, Et, Pr) and Et2Se and PhEtSe. The
complexes, which have the ligands L trans
to each other, have been studied by 1H, 13C N.M.R.,
low-frequency infrared and electronic spectroscopy. Low-temperature 1H
N.M.R. investigations were of assistance in determining the structure of the
complexes.
Reactions of Hex-3-yne with Dicarbonyl(η-cyclopentadienyl)-cobalt and -rhodium
Authors: Dickson RS , Johnson SH
Published: September 2010

The reaction of hex-3-yne
with (η-C5H5)Co(C0)2 gives the p-benzoquinone complex (η-C5H5)Co-[(EtC2Et)2(C0)2]
and the cyclopentadienone complex (q-C5H5)Co[(EtC2Et)2CO].
The corresponding reaction with (q-C2H2)Rh(CO)2 gives the cyclopentadienone complex (η-C5H5)Rh[(EtC2Et)2C0] and a binuclear
4,6-diethylnonadien-5-one complex, (η-C5H5)2Rh2(EtC2Et)2Co.
The 1H N.M.R. spectra of all complexes have been analysed, in some
instances with the aid of partial decoupling experiments. An analysis of the 13C
N.M.R. spectra of the two cyclopentadienone complexes is also given.
Chemistry of the Coccoidea. IV. Polyhydroxyanthraquinones and their glucosides from Eriococcus coriaceus (Hemiptera: Insecta)
Authors: Banks HJ , Cameron DW , Crossley MJ
Published: September 2010

A group of seven polyhydroxyanthraquinones based on emodin and the new
2-acetylemodin has been isolated from the eriococcid Eriococcus coriaceus Maskell.
Their structures have been established by chemical interconversion,
spectroscopic analysis and comparison with known substances. They occur in the
living insects as O-glucosides, four of which were isolated pure. Glucosylation has been shown to involve the oxygen
substituent at position 8 by a convenient p.m.r.
spectroscopic procedure developed for the purpose. Aqueous extracts of E. coriaceus show glucosidase activity towards aryl substrates.
Synthesis of 5,7-dihydroxynaphthoquinone derivatives and their reactions with nucleophiles: Nitration of 2,3-dimethylnaphthalene and subsequent transformations
Authors: Banks HJ , Cameron DW , Crossley MJ , Samuel EL
Published: September 2010

5,7-Dihydroxy-2,3-dimethyl-l,4-naphthoquinone
(5) and related compounds have been synthesized. The quinone affords an
accessible substrate for studying an unusual reaction with nucleophiles, which
involves attack at the 8-position, i.e. at the benzenoid ring. An unsuccessful
approach to (5) has led to tri- and tetra-nitro derivatives of
2,3-dimethylnaphthalene. Reduction of the former and subsequent conversions
have given aminonaphthoquinone and perimidinone derivatives.
Synthesis of (±)-cacalol
Authors: Yuste F , Walls F
Published: September 2010

The total synthesis of (�)-cacalol (1), a sesquiterpene isolated from the roots of Cacalia decomposita,
is described.
Ethenyl and ethynyl derivatives of Tricarbonyl(η-cyclobutadiene)iron
Authors: Nunn EE
Published: September 2010

Tricarbonyl(1-4-η-ethenylcyclobutadiene)iron
and a number of its derivatives (3a-d) have been prepared in good yield from
tricarbonyl(η- cyclobutadienecarbaldehyde)iron
(2) by reaction with methylenetriphenylphosphoranes.
Reaction of (E)- and (Z)- tricarbonyl[methyl 2-bromo-3-(η-cyclobutadienyl)propenoate]iron, (3b) and (3c), with
potassium t-butoxide gave tricarbonyl[methyl 3- (η- cyclobutadienyl)propynoate]iron
(4a) in low yield. Attempts to prepare tricarbonyl(1-4-η-ethynyl-cyclobutadiene)iron
(4b) by debromination of tricarbonyl[1-4-η-(2?,2?-dibromoethenyl)cyclobuta-diene]iron(3d)
were unsuccessful.
E.S.R. studies of the solute-solute interactions between copper(II) and nickel(II) thiosemicarbazone chelates in non-aqueous solutions
Authors: Bolfo JAD , Smith TD , Boas JF , Pilbrow JR
Published: September 2010

The X-band e.s.r. spectra
due to the copper(II) chelates of the thiosemicarbazones salicylaldehyde
thiosemicarbazone (stsc), salicylaldehyde
4-methyl(thiosemicarbazone) (smtc), salicylaldehyde
4- ethyl-(thiosemicarbazone) (setc), salicylaldehyde
4- phenyl(thiosemicarbazone) (sptc),
2-hydroxyacetophen- one 4- ethyl(thiosemicarbazone) (aetc)
and 2-hydroxypropiophenone 4- ethyl(thiosemicarbazone) (petc)
dissolved in various organic solvents have been studied at room temperature and
down to 77 K. The e.s.r. spectra show evidence of hyperfine structure due to
the 14N nucleus of the ligand. Addition of the nickel(II) chelate of
the thiosemicarbazone ligands to organic solvent solutions of the corresponding
copper(II) chelate brings about a profound change in the e.s.r. spectrum of the
copper(II) chelate in frozen solution. These changes are interpreted as arising
from a change in the ground state of the copper(II) ion from essentially dx2-y2
to d3z2-r2, which arises as a result of specific solute- solute
interactions between the copper(II) and nickel(II) chelates.
γ-Radiation-induced carboxylation of pyrrolidine
Authors: Davison A , Barker NT , Sangster DF
Published: September 2010

Amino acids produced in the
γ-radiation-induced carboxylation of pyrrolidine and formate in neutral
aqueous solution have been studied. Two products only were found in the ratio 1
: 5.5. The minor product, proline, and the major product, pyrrolidine-3-carboxylic
acid, have been characterized. Their presence indicates that the predominant
site of hydrogen abstraction from pyrrolidine by radiation-generated hydroxyl
radicals is β to the amino group.
Chemistry of hydrofluorenones. II. Synthesis from cyclohexyl benzoates
Authors: Ng KSN , Roberts JL , Rutledge PS , Wilson MA , Woodgate PD
Published: September 2010

Synthetically useful
substituted hexahydrofluoren-9-ones and hexahydrobenzofluoren-11-ones may be
prepared in one step from cyclohexyl benzoates or naphthoates and
polyphosphoric acid. When the hydrindanone ring junctions are unsubstituted the
stereochemistry may be determined from the 1H N.M.R. spectra by
decoupling the spectra after addition of a paramagnetic shift reagent.
3-Hydroxyphysodic acid. Chemical corroboration of the structure of this lichen depsidone
Authors: Elix JA , Engkaninan U
Published: September 2010

The published structure of
the lichen depsidone ?physodol? has been shown to be
incorrect. This compound is in fact identical with 3- hydroxyphysodic
acid (2) (1?-carboxy-2?,3,4-trihydroxy-6-(2?- oxoheptyl)-6?-pentyldepsidone).
��� Chemical evidence is presented to confirm
the isocoumarin structure (10) for that of the key decarboxy anhydro derivative
obtained by degradation of 3-hydroxyphysodic acid, and thus to disprove the
alternative 5-hydroxy formulation suggested for this compound.
Metal-ammonia reduction and reductive alkylation of conjugated dienoic acids
Authors: Birch AJ , Slobbe J
Published: September 2010

Conjugated dienoic acids
are readily reduced or reductively alkylated with lithium-ammonia to their
trans-β,γ-unsaturated and trans-α-alkyl-
β,γ-unsaturated derivatives respectively.
Competing protonation in the latter reaction detracts from its general use in
synthesis; the origin of this side reaction is briefly discussed.
Thermodynamics of metal-ligand bond formation. XXV. Addition of bases to Bis[O,O'-diethyl thiomalonato]nickel(II) in various solvents
Authors: Ang L , Graddon DP , Ng VAK
Published: September 2010

Thermodynamic data have
been obtained from spectroscopic and calorimetric measurements for the addition
of pyridine and 4- methylpyridine to bis(O,O?-diethyl thiomalonato)nickel(II),
Ni(etm)2, in solution in cyclohexane,
benzene, 1,2-dichloroethane, acetonitrile, butan-2-one and carbon tetra-chloride.
In each solvent two base molecules add successively, giving Ni(etm)2B then Ni(etm)2B2.
There are only small variations in K1 and K2 in different
solvents; typically K1 ≈ 200, K2 ≈ 100 l. mol-1,
ΔH�1+2 ≈ -65, ΔH�2 ≈ 0 kJ mol-1
at 30�C, but in benzene and cyclohexane ΔH�2 ≈ -25 and in
cyclohexane ΔH�1+2 ≈ -100 kJ mol-1. The main
driving force for adduct formation is apparently the formation of the first
Ni-N bond, which is accompanied by a spin change.
Potential wool growth inhibitors. 2(1H)-Pyridone analogues of mimosine
Authors: Harris RLN , Teitei T
Published: September 2010

The syntheses of
DL-α-amino-β-(5-hydroxy-6-oxo-1,6-dihydropyridin-2- yl)propionic acid
(3) and DL-α-amino-β-(1-hydroxy-2-oxo-1,2- dihydropyridin-4-yl)propionic
acid (4), 2(1H)-pyridone isomers of the naturally occurring depilatory amino
acid L-mimosine (1), are described.
Adsorption of calcium at the zinc sulphide-water interface
Authors: Moignard MS , James RO , Healy TW
Published: September 2010

The uptake of aqueous calcium ions by pure zinc sulphide colloids has been measured by direct
adsorption and microelectrophoresis techniques. This uptake is pH dependent, with significant
adsorption commencing at approximately pH 7 and increasing up to pH 11. The electrokinetic
measurements also reflect the interfacial presence of Ca2+. The zeta-potential of zinc sulphide
particles is more positive in the presence of Ca(NO3)2 solutions than in simple background electrolyte
(KNO3) solutions. If the concentration of calcium ion is sufficiently high, the zeta-potential changes
sign c. pH 8.
Adsorption and simple ion-exchange models which have been successfully applied to other
oxide and sulphide minerals are not particularly successful. However, reasonable agreement between
direct adsorption and electrophoresis data has been obtained from the simple Gouy-Chapman-Stern
double layer model, provided that: (i) the surface potential is approximately given by the Nernst
equation; (ii) the specific adsorption potential of Ca2+ on ZnS increases from about 0 kBT/ion,
at low pH values below pH 7, up to about - 6.5 kBT/ion, at pH 8 and higher.
An ion-exchange model could only be used to give reasonable agreement with experiment at low
adsorption densities. This exchange reaction is not strongly pH dependent and involves the release
of one proton for every three Ca2+ ions adsorbed.
These results would indicate that Ca2+ adsorption at the ZnS-H2O interface involves the
movement of calcium ions into the Stern plane without the release of an equivalent number of protons
into the diffuse layer and bulk solution. The subsequent decrease in zeta-potential caused by Ca2+
adsorption may be related to deteriorating flotation recoveries and grades observed for sphalerite
in the presence of Ca2+ solutions when lime is used as a pH modifier and/or suppressant for pyrite.
Carbon-13 nuclear magnetic resonance spectroscopy of naturally occurring substances. LI. Solanum glycoalkaloids
Authors: Weston RJ , Gottlieb HE , Hagaman EW , Wenkert E
Published: September 2010

.The 13C n.m.r. spectra of the glycoalkaloids solasonine and tomatine, as well as of their naturally
occurring aglycones solasodine and tomatidine, were recorded and the signals assigned completely.
The carbon shifts confirm the proposed stereochemistry at the spiro ring junction.
Measurement, employing 1H and 13C spin-lattice relaxation times, of the temperature dependence of the correlation time for rotational reorientation (τR)of diamagnetic transition-metal Bis- and Tris-acetylacetonate complexes
Authors: Doddrell DM , Bendall MR , O'Connor AJ , Pegg DT
Published: September 2010

1H and 13C nuclear relaxation times for the
ligand positions of Pd(acac)2 and Co(acac)3 (acac = acetyl-acetonate)
have been measured as a function of temperature. Nuclear Overhauser enhancement
factors are used to demonstrate that except for the methyl carbon nucleus
internuclear dipolar interactions dominate the relaxation times. Consequently TR
can be extracted from the data. It is found that TR for a 0.05 M
solution in CDCl3 varies with temperature (T) as

TR = 3.92x10-13exp(1.38x103/T) (Co)

TR = 4.42x10-13exp(1.20x103/T) (Pd)

Activation energies for
rotational reorientation calculated from the data are found to be 9-10 kJ mol-1
for both complexes. There appears to be a slight concentration dependence of ER,
ER being about 12 kJ mol-1 for a 0.2 M solution of the
palladium complex. Spin internal reorientation affects the T1 value
of the CH3 carbon of Pd(acac)2,
with T1 getting shorter as the temperature is raised. A simple single-axis model of rotational
reorientation in solution is presented whereby it can be shown that ER
is the average barrier energy encountered by a molecule during a single angular
reorientation.
A 13C nuclear magnetic resonance study of glycals (1,5-Anhydro-hex-1-enitols)
Authors: Burfitt AIR , Guthrie RD , Irvine RW
Published: September 2010

A series of D-allal and D-glucal derivatives were examined by 13C
N.M.R. spectroscopy. Assignments of 13C resonances were established
by standard chemical shift considerations, lanthanide shift reagent and proton
chemical shift correlations. Configuration-induced chemical shift variations
are reported between the glucal and allal systems.
Reduction by dissolving metals. XXII. Reduction and reductive alkylation of some Methoxy- and Dimethylamino-benzoic acids
Authors: Birch AJ , Slobbe J
Published: September 2010

Reductions by lithium in
ammonia of 2-, 3- or 4-methoxy- or 2- or 4- dimethylamino-benzoic acids result
in total loss of 4-OMe and 4-NMe2, and partial loss of 2-OMe. In the
presence of methanol loss of 2-OMe is minimized. Intermediate dianions can be
alkylated to the corresponding 1-alkyl-1,4-dihydrobenzoic acids which in some
cases are useful intermediates in synthesis. A useful new procedure for
synthesizing 2- alkylcyclohex-2-enones is described.
Insecticides. XIII. Crystal structure of isobenzan (exo-1,exo-3,4,5,6,7,8,8-Octachloro-1,3,3a,4,7,7a-hexahydro-endo-4,7-methanoisobenzofuran)
Authors: Smith G , Kennard CHL
Published: September 2010

The crystal structure of
isobenzan was determined by direct methods. The crystals are monoclinic, (C2/c)
with Z = 16, in a cell of dimensions a = 2571(1), b = 1735(2), c = 1361(1) pm;
β = 100.65(1)�. The structure was refined by least squares to R 0.073 with
1650 unique reflections collected on an automated equi-inclination
diffractometer. The two molecules (A, B) of isobenzan in the asymmetric unit
are similar and possess the exo-1,exo-3-chlorine arrangement and the endo
tetrahydrofuran configuration, previously proposed on the basis of chemical
evidence. This results in the molecules possessing approximate Cs(m)
point symmetry with the bridgehead carbon and its attached chlorines, and the
epoxide oxygen lying in the mirror plane. There is no evidence of intermolecular
association involving oxygen or chlorine.
Photooxidation of 3-Methylindoles
Authors: Evans NA
Published: September 2010

Ultraviolet photolysis of
3-methylindole gives 2-formamidoacetophenone (2?-acetylformanilide) and
3-methylindole-2-carbaldehyde whereas photolysis of 2-ethyl-3-methylindole
gives 2-acetyl-3-methylindole and 2-propionamidoacetophenone (2?-acetylpropionanilide).
The yields of these products and the rate of photolysis of 3-methylindole are
dependent on the solvent. Possible mechanisms for the photolysis of 3- methylindole
are discussed.
(Z)- and (E)-3,3'-(1,2-Ethenediyl)bispyridines
Authors: White PY , Summers LA
Published: September 2010

(Z)-3,3?-(1,2-Ethenediyl)bispyridine
has been prepared by decarboxylation of (Z)-2,3-di(3-pyridyl) acrylic acid and
converted into (E)-3,3?-(1,2-ethenediyl)bispyridine by heating in nitrobenzene
in the presence of iodine.
Synthesis of N-substituted glutarimides
Authors: Cameron DW , Down JG , Kissane PJ , Laycock GM , Shulman A
Published: September 2010

A series of N-alkyl- and
N-benzyl-glutarimides related to bemegride have been synthesized both by the
Guareschi procedure and by N- alkylation.
Solvation of ions. Some applications. III. Solutions of copper(I) salts in water containing ligands
Authors: Parker AJ , Clarke DA , Couche RA , Miller G , Tilley RI , Waghorne WE
Published: September 2010

Solutions of copper(II) and
copper(I) sulphate in water containing acetonitrile have applications in the
hydrometallurgy of copper. The potentials (n.h.e.) of the Cu+/Cu;
the Pt/Cu2+, Cu+, and the Cu2+/Cu electrodes
in water containing a large molar excess of various copper(I) bases and various
counter-anions have been measured. Free energies of transfer of copper(I) ions
from water to water containing the bases are calculated. ΔGtr(Cu+)
at 25�C becomes less exoenergetic for water containing the bases in the
following order: CN- >> S2O32-
> Me2NCHS > KI > NH3 > C5H5N
> KBr > KCl > C3H5OH ≥ MeCN, CO, C2H4
> C3H6. The reduction potentials of CuSO4/Cu2SO4
in acidic saturated copper(II) sulphate solutions and a range of Cu2SO4
concentrations in acetonitrile- water mixtures show that CuSO4/MeCN/H2O
is a powerful oxidant, comparable in strength to acidic iron(III) sulphate in
water. Acetonitrile is the preferred base for the processing of copper by way
of solutions of copper(I) sulphate.
Crystal structures of Bis[tricarbonyl(η-cyclopentadienyl)molybdato(0)]mercury(II) and trans-Dicarbonyl(dimethylphenylarsine)[iodomercurio(0)](η-methylcylopentadienyl) molybdenum(II)
Authors: Mickiewicz MM , Raston CL , White AH , Wild SB
Published: September 2010

The crystal structures of
the title compounds [Hg{Mo(CO)3(C5H5)}2]
(1) and [IHg{Mo(CO)2- (C5H4Me)(AsPhMe2)}]
(2) have been determined by X-ray diffraction at 295 K and refined by least
squares to residuals of 0.065 and 0.079 for 867 and 1313 ?observed? reflections
respectively. ��� [Hg{Mo(CO)3(C5H5)}2]
is monoclinic, C2/c, a = 21.161(5), b = 7.106(1), c = 12.103(2) Ǻ, β
= 91.23(2)�, Z = 4. [IHg{Mo(CO)2(C5H4Me)(AsPhMe2)}]
is monoclinic, P21/a, a = 24.784(8), b = 7.751(3), c = 9.949(3) Ǻ,β = 105.16(3)�, Z = 4. The molecule in (1) has
symmetry 2. Coordination about the mercury is substantially linear in both
cases: (1) Mo-Hg-Mo 173.71(6)�, Hg-Mo 2.746(2) Ǻ; (2) Mo-Hg-I 167.40(8)�,
Hg-Mo 2.685(3), Hg-I 2.720(3), Mo-As 2.536(4) Ǻ.
Pyrimidine reactions. XXVI. 2-(1'-Bromo-1'-methylethyl)pyrimidines: Synthesis, solvolysis and dehydrobromination to 2-Isopropenylpyrimidines
Authors: Brown DJ , Waring P
Published: September 2010

Synthetic routes to
2-isopropyipyrimidine (2b) and to its 4-phenyl and 4-methoxy derivatives, (2e)
and (2h), are outlined. These pyrimidines undergo α-bromination by N-bromosuccinimide
to give the 2-(1?-bromo-1?- methylethyl)pyrimidines (2c), (2f) and (2i)
respectively. In methanol, controlled at neutrality, these bromo derivatives
give the corresponding 1?-methoxy compounds (2j-l) but in methanolic sodium
methoxide, each undergoes dehydrobromination to the appropriate 2- isopro-penylpyrimidine (3; R = H, Ph or OMe):
these are confirmed as olefins by N.M.R. spectra and by the conversion of the
second (3; R = Ph) into its epoxide (4). First-order rate constants for
solvolysis of the bromo derivatives in 50% aqueous methanol, maintained at
apparent pH 7.0, are recorded and discussed.
The kinetics of the base hydrolysis of trans-Dichloro- and trans-Dibromo-(meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene)cobalt(III) perchlorate
Authors: Kendall PL , Lawrance GA
Published: September 2010

The kinetics of the
successive base hydrolysis of both halogen ligands in trans-[Co(hctd)Cl2]+
and trans-[Co(hctd)Br2]+ (hctd = meso-
5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) have been
investigated at 25�C in formic acid-NaOH buffers (pH range 3.0-3.7) and 2,6-lutidine-perchloric
acid buffers (pH range 6.4-7.4). Hydrolysis reactions in each buffer system,
consistent with release of first and second coordinated halogen respectively,
follow rate expressions of the type kobs = kaq+ kOH]OH-],
with base hydrolysis rates kOH? = 7.8(�0.8) x 108 dm3
mol-1 s-1 and 1.9(�0.3)x109 dm3 mol-1
s-1 respectively for first chloride and bromide hydrolysis, and kOH?
= 7.3(�0.4)x104 dm3 mol-1 s-1 and
2.4(�0.2)x105 dm3 mol-1 s-1 for
second chloride and bromide hydrolysis respectively. Comparison with the analogous
complex trans-[Co(dtcd)Cl2]+ (dtcd = meso-5,12-dimethyl- 1,4,8,11-tetraazacyclotetradeca-4,11-diene)
shows a ninefold acceleration for base hydrolysis of the first chloride in the
hctd complex over the dtcd complex, but an 80-fold rate retardation for base
hydrolysis of the second chloride in the hctd complex compared with the dtcd
complex, interpreted in terms of steric effects arising from gem- dimethyl
substitution in the hctd ligand.
Hydroxamic acids: VI. The synthesis, properties and reactions of amidic hydroxamic acid and dihydroxamic acid derivatives
Authors: Hearn MTW , Ward AD
Published: September 2010

Amidic hydroxamic acid and
dihydroxamic acid derivatives of maleic, phthalic, fumaric and succinic acids have been prepared and their properties and
reactions studied. In particular suitably oriented derivatives of these systems
have been investigated to ascertain whether they are capable of existing in, or
reacting through, various cyclol tautomers. Attempts to trap the cyclol
tautomers are described and these results, together with other indirect
chemical evidence as well as the spectral data, suggest that the cyclol
tautomer may be present in some cases, in contrast to the corresponding
diamides which do not show similar behaviour.
Molecular orbital calculations on dinitrogen trioxide, N2O3
Authors: Doonan IJ , Maclagan RGAR
Published: September 2010

A minimal Slater basis set
molecular orbital calculation on dinitrogen trioxide, N2O3,
is reported. In the evaluation of integrals, non-NDDO integrals were calculated
by the 3G/s expansion technique. Analysis of the wave function obtained shows
weak bonding between the nitrosyl and nitro fragments and a very weak
attractive interaction between the cis- oxygens. The molecular orbitals for N2O3
were expanded in terms of the NO and NO2 molecular orbitals. A correlation
diagram linking the N2O3 orbitals with the NO and NO2
orbitals is presented. The localized molecular orbitals for N2O3
are analysed. A configuration interaction calculation involving the ground
state and nine doubly excited state configurations is reported. Two excited
states have significant contributions. A comparison is made between the results
obtained by using a 3G/S expansion and a calculation using a 2G/S expansion.
Chemistry of the Group 1B metals. X. Reactions between silver arylacetylides and some rhodium(I) and iridium(I) complexes
Authors: Salah OMA , Bruce MI
Published: September 2010

Reactions between AgC2Ar
(Ar = Ph or C6F5) and RhCl(PPh3)3
or IrCl(CO)(PPh3)2 have given hexanuclear heteroatom
cluster compounds M2Ag4(C2Ar)8(PPh3)2
(M = Rh or Ir), and the zwitterionic complexes {[Ag(PPh3)]+
[M(C2C6F5)4(PPh3)2]-}
and {[Ag(PPh3)]2+ [Rh(C2C6F5)5(PPh3)]

2-}.The structures of these complexes are described and
discussed, together with possible reactions by which they may be formed.
Coordination compounds of Hg22+: The crystal structure of Tetrakis-(4-benzylpyridine)dimercury(I) perchlorate
Authors: Taylor D
Published: September 2010

Crystals of tetrakis(4-benzylpyridine)dimercury(I)
perchlorate, [Hg2(C12H11N)4]2,
(ClO4)2, are monoclinic,a
11.729(1) Ǻ, b 10.896(1) Ǻ, c 18.392(2) Ǻ, β 96.20(1)�,
space group P21/c with Z = 2 dimeric formula units. The structure
was solved from three-dimensional diffractometer data (2744 independent
reflections) by Patterson and Fourier techniques. Block-diagonal least-squares
refinement of all non-hydrogen atoms converged at R 0.039, Rw 0.053.
The mercury atoms in the centrosymmetric cation are three-coordinate with Hg-Hg
2.5084(7), Hg-N 2.227(7), 2.476(7) Ǻ. The Hg-Hg-N angles are 153.9� and
118.4� respectively. The perchlorate ions span the Hg-Hg bond with long Hg-O
contacts of 2.899 and 3.026 Ǻ. This is a new structural type for
dimercury(1) coordination compounds. The distortion of the usually linear L-Hg-Hg-L
system with the increase in coordination number of the mercury atoms appears to
be related to the stability of dimercury(I) complexes with moderately basic
N-donor ligands.
Pyrolysis of aryl azides. IV. Neighbouring group effects by ortho carbonyl groups
Authors: Dyall LK
Published: September 2010

The question of the
mechanism by which ortho carbonyl groups enhance the rate of pyrolysis of aryl
azides is examined. Rate measurements on sterically hindered 1-(2-azidophenyl)ethan-1-ones
are consistent with the pericyclic mechanism proposed by Dyall and Kemp1
but not with the intramolecular 1,3-dipolar addition route put forward by Hall,
Behr and Reed.2 A definitive test of mechanism is also provided by
1- azidoanthraquinone and 1-(2-azidophenyl)-2,2-dimethylpropan-1-for both of
which the formation of a 1,3-dipolar adduct is precluded on steric grounds but
the pericyclic process is not. At 393.2 K, these two azides pyrolyse 7385 and
61.7 times faster than phenyl azide, respectively.
Aluminium-chloride-promoted reactions of ethyl acrylate with olefins
Authors: Beckwith ALJ , Moad G
Published: September 2010

Contrary to an earlier
report,1 the aluminium-chloride-promoted reaction of ethyl acrylate
with olefins does not afford cyclobutane derivatives. In benzene, ethyl
acrylate reacts with isobutylene or 2,3-dimethylbut- 2-ene to afford the
terminally unsaturated products (5) and (9) respectively. In 1,2-dichloroethane-nitromethane
the initial products undergo isomerization or rearrangement. Un-ambiguous
routes to 2,2- dimethylcyclobutanecarboxylic acid
(19) and (2,2,3,3- tetramethylcyclobutyl)- methanol
(26) are described.
Tridentate and unsymmetrical tetradentate Schiff base ligands from salicylaldehydes and diamines: Their monomeric and dimeric nickel(II) complexes
Authors: Elder RC
Published: September 2010

A series of ligands has
been formed by the 1 : 1 molar condensation of salicylaldehyde (sl) with the diamines, propane-1,3-diamine (p),
butane-1,4-diamine (b) and 2,5-dimethylhexane-2,5-diamine (d). The potentially
tridentate ligands are o-[N-(3- aminopropyl)formimidoyl]phenol
(Hslp), o-[N-(4- aminobutyl)formimidoyl]phenol (Hslb) and o-[N-(4-amino-1,1,4- trimethylpentyl)formimidoyl]-phenol
(Hsld), respectively. These form the bis-nickel(II)
complexes Ni(slp)2, Ni(slb)2
and Ni(sld)2. All appear to have octahedral structures
in the solid. Ni(slb)2 occurs in yellow
and green forms in the solid. In solution Ni(sld)2
occurs in equilibrium between tetrahedral (amines uncoordinated) and an
octahedral centrosymmetric form with facially bound sld
ligands. Ni(slp)2 reacts with
bis(5-chloro-salicylaldehyde)nickel(II) to give the unsymmetrical
four-coordinate nickel complex formed from the 1 : 1 : 1 molar condensation of
salicylaldehyde, propane-1,3-diamine and 5- chlorosalicylaldehyde.
A dimeric, amido bridged complex has been produced by the vacuum thermolysis of
Ni(slp)2. Mass spectroscopic evidence is
cited for the formation of the analogous dimeric complexes from Ni(slb)2 and Ni(sld)2.
Studies on chloroplast membranes. III. 13C chemical shifts and longitudinal relaxation times of 1,2-Diacyl-3-(6-sulpho-α-quinovosyl)-sn-glycerol
Authors: Johns SR , Leslie DR , Willing RI , Bishop DG
Published: September 2010

13C Chemical shifts, longitudinal relaxation times and
some nuclear Overhauser enhancement factors of the individual carbon atoms in
the chloroplast lipid, 1,2-diacyl-3-(6-sulpho-α-quinovosyl)-sn-glycerol (sl), have been
measured in the three solvents: methanol[D4], chloroform[D] and
water[D2]. Correlation times for the individual carbon atoms
calculated from these results have been interpreted in terms of different
secondary structures: a monomeric structure in methanol[D4], an
inverted micellar structure in chloroform[D] and a bilayer vesicular structure
in water[D2]. Substituent shift parameters have been
determined for the sulphonic acid group from a series of alkanesulphonic acids
and these have been used in the 13C chemical shift assignments in sl and a series of model compounds.
Perchlorate and difluorophosphate coordination derivatives of manganese carbonyl
Authors: Wimmer FL , Snow MR
Published: September 2010

The complexes Mn(CO)5(OClO3) and Mn(CO)3L2(OClO3) (L = PPh3,
P(OPh)3; L2 = bpy*)
are formed by abstraction reactions with AgClO4 from the corresponding
bromo complexes in dichloromethane. The perchlorato complexes have been
characterized by i.r. and mass spectroscopy. They
undergo facile substitution reactions in which the perchlorato group is
replaced by halide ions (X- = Cl, Br, I),
phosphines [PR3 (R = Ph, p- tolyl, m-tolyl), dpe,
dpm]* or solvent molecules (MeCN,
PhCN, MeOH, Me2CO,
py*). Reaction with fluoride ion yields Mn(CO)3F3 plus other decomposition
products. When Mn(CO)5X and Mn(CO)3L2X (X = Br) are made to react
with AgPF6 in dichloromethane, hydrolysis of the PF6-
ion occurs to yield the corresponding difluorophosphato complexes (X = PO2F2-),
which have been characterized by i.r., 19F
N.M.R. and mass spectroscopy. They are reasonably stable at low temperatures,
but decompose at room temperature. The difluorophosphato group is more inert
than perchlorato with the rate of substitution decreasing in the order CO
≈ PPh3 > bpy > P(OPh)3.
Catalytic hydrogenation of isoflavones. The preparation of (±)-equol and related isoflavans
Authors: Lamberton JA , Suares H , Watson KG
Published: September 2010

Hydrogenation of daidzein,
or preferably its O,O-diacetyl derivative, gives (�)-equol
in good yield only over Pd/C prepared according to the Wessely and Prillinger
method, whereas other Pd/C catalysts give mixtures of products. Hydrogenation
of O,O,O-triacetylgenistein can be used to prepare isoflavan-4',5,7-triol.
Dinitration of 1-Methylpyrazole: 1-Methyl-3,4-dinitropyrazole
Authors: Grimmett MR , Lim KHR
Published: September 2010

Nitration in 80% sulphuric
acid of 1-methylpyrazole gives 1-methyl-4- nitropyrazole and 1-methyl-3,4-dinitropyrazole
in a 4 : 1 ratio. The dinitro compound is also formed by nitration of 1-methyl-3-
nitropyrazole.