Sodio Derivative Research Articles

(NHC)Cu-Catalyzed Mild C–H Amidation of (Hetero)arenes with Deprotectable Carbamates: Scope and Mechanistic Studies

Primary arylamines are an important unit broadly found in synthetic, biological, and materials science. Herein we describe the development of a (NHC)Cu system that mediates a direct C-H amidation of (hetero)arenes by using N-chlorocarbamates or their sodio derivatives as the practical amino sources. A facile stoichiometric reaction of reactive copper-aryl intermediates with the amidating reagent led us to isolate key copper arylcarbamate species with the formation of a C-N bond. The use of (t)BuONa base made this transformation catalytic under mild conditions. The present (NHC)Cu-catalyzed C-H amidation works efficiently and selectively on a large scale over a range of arenes including polyfluorobenzenes, azoles, and quinoline N-oxides. Deprotection of the newly installed carbamate groups such as Boc and Cbz was readily performed to afford the corresponding primary arylamines.

Insertions of phenylacetylene with chelated bis(triphenylphosphine) - ruthenium(II)hydridocarbonyl complexes

Phenylacetylene reacts stoichiometrically or in excess with the Ru—H bond of RuH(CO)(PPh3)2(L) (LH = 2-hydroxypyridine, 2-hydroxy-6-methylpyridine, acetylacetone, benzoylacetone, 2-hydroxyacetophenone, 2-hydroxypropiophenone, 2-hydroxybenzophenone and 4-methoxy-2-hydroxybenzophenone) in boiling benzene to give σ-vinylic or σ-vinylalkynyl complexes of the type Ru(CO)-(PPh3)2(L)(CH\( = \)CHPh) and Ru(CO)(PPh3)2(L){C-(C\( \equiv \)CPh)\( = \)CHPh} in good yield. The vinylic complex can also be obtained by reacting the sodio derivative of the chelating ligand with the 16e− unsaturated complex, [Ru(CO)Cl(CH\( = \)CHPh)(PPh3)2], in CH2Cl2/MeOH mixture at ambient temperature. These complexes have been characterized by elemental analyses, and i.r., 1H, 13C and 31P n.m.r. spectroscopy.

N-halogeno compounds. Part 12 [1]. Site-specific fluorination of carbanions with perfluoro-N-fluoropiperidine [2

Perfluoro- N-fluoropiperidine ( 1) acts as a site-selective electrophilic fluorinating agent towards carbanionic substrates [Me 2CNaNO 2 → Me 2 CFNO 2; PhMgBr → PhF; PhCNa(CO 2Et) 2 → PhCF(CO 2Et) 2; EtCNa(CO 2Et) 2 → EtCF(CO 2Et) 2; CH 2(CH 2) 2COC NaCO 2Et → CH 2(CH 2) 2COC FCO 2Et], but in doing so is converted to perfluoro-1- azacyclohexene (2). Unfortunately, this imidoyl fluoride ( 2) is highly electrophilic and competes with the NF compound ( 1) for carbanionic species, as exemplified by the formation of the 2-substituted octafluoro-1-azacyclohexenes CF 2(CF 2) 3NC R, where R = Ph, CEt(CO 2Et) 2, and C(CO 2Et)CO(CH 2) 2C H 2 in the respective cases of the last three sodio derivatives listed above.

N-halogeno compounds. Part 11. Perfluoro-[N-fluoro-N-(4-pyridyl)-methanesulphonamide], a powerful new electrophilic fluorinating agent

Perfluoro-[ N -fluoro- N -(4-pyridyl)methanesulphonamide] (III), synthesised via direct fluorination of the sodio derivative of perfluoro-[ N -(4-pyridyl)methanesulphonamide] (I), readily converts diethyl sodio(phenyl)malonate and anisole to diethyl fluoro(phenyl)malonate and ortho - plus para -fluoroanisole respectively at ambient temperature; at 60 °C it quickly converts benzene to fluorobenzene. The sodio-precursor (I) of the N-F compound (III) is easily made from pentafluoropyridine and trifluoromethanesulphonamide.

Synthèse, caractérisation et réactivité de l'ester diméthylique de l'acide (η-2,3,4,5) nonadiényl-(2E, 4E)-phosphonique fer tricarbonyle

Abstract A facile route is described to the dimethyl ester of (2,3,4,5-η)-( 2 ,4 E )-nonadienyl phosphonic acid tricarbonyliron ( 6 _which is obtained in an overall yield of 36% from (2 E ,4 E )-nonadienal. The stable sodio derivative of 6 , when treated with sterically non-crowded aldehydes, gave the corresponding ( E )-ene tricarbonyliron complexes in yields of 45–90%. Deuterium labelling experiments excluded any bond-shift isomerisation during the Wittig-Horner reaction.

Synthesis of alkylated methylene bisphosphonates via organothallium intermediates

Thallium(I) derivatives of esterified methylene bisphosphonates can be readily obtained by treating the latter with thallium(I) ethoxide under anhydrous conditions. Alkylation of the thallium(I) derivatives by a range of primary alkyl iodides takes place smoothly, and significantly higher yields are obtained than for the corresponding reactions with lithio or sodio derivatives.

Some heterocyclic sulfonyl chlorides and derivatives

AbstractThe syntheses of 4‐ and 5‐chlorosulfonylfuran‐2‐carboxylic acid (Ia,IIa), 4‐chlorosulfonylfuran‐2‐carboxamide (Ib), 3,5‐dimethylpyrazole and isoxazole‐4‐sulfonyl chlorides (IIIa,IVa) and 2,4‐dimethylthiazole‐5‐sulfonyl chloride (Va) are described. The sulfonyl chlorides were converted into a range of amides, hydrazides and azides. Condensation of the sulfonohydrazides with β‐dicarbonyl compounds, gave the corresponding β‐ketohydrazones (VII), which, with the exception of the derivatives (VIIe,f,g,i), were converted to the sulfonylpyrazoles (VIII). The structures and spectral data of these compounds are briefly discussed. The reaction of the sodio derivative of acetylacetone with thiophene‐2‐sulfonyl chloride (VIc) gave 3‐(thiophene‐2‐sulfonyl)pentane‐2,4‐dione (XII), which with hydrazine gave 4‐(thiophene‐2‐sulfonyl)‐3,5‐dimethylpyrazole (XIII). However, the analogous reaction with thiophene‐2‐sulfonohydrazide (VIa) failed to give the expected 1,4‐bisthiophenesulfonylpyrazole.

A convenient synthesis method for methylenomycin B and its application to methylenomycis A.

A convenient synthesis method for methylenomycin B and its homolog, methylenomycin A, has been developed. Methylenomycin B, 2,3-dimethyl-5-methylene-2-cyclopentenone (3) was synthesized: i) by methylation of Mannich derivative prepared from morpholine and 2,3-dimethyl- 2-cyclopentenone (5) or ii) by treatment of formalin with sodio derivatives of 2,3-dimethyl-5-formyl-2-cyclopentenone (7a) and 2,3-dimethyl-5-ethoxalyl-2-cyclopentenone (7b), both of which were easily prepared from 5 and ethyl formate or ethyl oxalate. 2,3-Dimethyl-2,3-epoxy-5-methylenecyclopentanone (2) was similarly prepared from the epoxide compound of 5 and ethyl oxalate. The bioassay ofmethylenomycin B and its related compounds against bacteria (B. subtilis, S. aureus, Ps. aeruginosa and E. coli) was also conducted. Methylenomycin A (1) and its desepoxy compound (17) were also prepared from 4-carboxy-2,3-dimethyl-2-cyclopentenone (15) in the same procedure as described above.

N-alkylation of 3,5-dicyano-2,4,4,6-tetramethyl-1,4-dihydropyridine with some α,ω-dihalogeno-N-alkenes

Bis-1,4-dihydropyridine derivatives Vc-Vf can be obtained on reaction of α,ω-diiodo-n-alkanes with the sodio derivative II of compound I, while α,ω-dibromo-n-alkanes give a mixture of compounds Vc-Vf and IVc-IVf. Analogous products IVa and Va,b could not be prepared, owing to the predominating and disturbing elimination reactions. Spectral characteristics (UV, IR, NMR and mass spectra) of the compounds obtained are confronted with their structure.

A simple procedure for .ALPHA.-methylenation of .GAMMA.- and .DELTA.-lactones.

α-Methylene γ- and δ-lactones can be prepared in fair yields by a two step procedure involving formation of the α-hydroxymethylene or α-ethoxyoxalyl sodio derivatives of γ- or δ-lactones followed by their condensation with formaldehyde.

Salts of Methyl-2-benzimidazole Carbamate (MBC) and Assessment of Their Potential in Dutch Elm Disease Control

Methyl-2-benzimidazole carbamate (MBC) was solubilized by formation of salts (MBC-phosphate, -nitrate, -hydrochloride, -sulfate, and -sodio derivative). All the salts of MBC exhibited greater fungitoxicity towards Ceratocystisulmi than the parent compound and lower phytotoxicity towards elms. MBC-phosphate was root injected into 12 healthy, mature, field-grown white elms (Ulmusamericana L.) and one with severe symptoms of Dutch elm disease. Controls consisted of seven elms injected with distilled water alone. To date, bioassays of trees treated with MBC-phosphate using the root-injection method have demonstrated extremely good distribution throughout the tree at a concentration which, on the basis of laboratory tests, is sufficient to arrest development of C. ulmi. Treated elms could not be successfully inoculated with C. ulmi conidia, whereas control trees could. Recovery of C. ulmi from the diseased elm was greatly reduced after root injection with MBC-phosphate.

Some Preliminary Observations on the Catalytic Fading of Dye Mixtures

The ‘catalytic fading’ of C.I. Acid Violet 4 in the presence of C.I. Acid Yellow 112 has been investigated in solution, on films and on fibres. Trace amounts of an impurity have been isolated from C.I. Acid Yellow 112. This impurity has been shown to fade C.I. Acid Violet 4 catalytically. Examination of the impurity and comparison of its properties with those of the sodio derivative of ethyl acetoacetate suggest that it is a β‐ketonic acid derivative present in part as an enolic sodium salt.

Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms—XIX Configurational and conformational studies with derivatives of hexahydropyrido [2,1‐c][1,4]oxazin‐4(3H)‐ones

AbstractA series of substituted hexahydropyrido [2,1‐c][1,4]oxazin‐4(3H)‐ones has been prepared by reaction of the sodio derivative of the appropriate piperidyl carbinol with ethyl chloroacetate. From a study of their NMR spectra the configurations of these compounds have been assigned and the conformation of the perhydro‐1, 4‐oxazinone moiety shown to be that with the ring oxygen atom and the angular hydrogen on the same side of the plane defined by C3C(O)N. The synthesis and NMR spectra of hexahydro‐2H‐pyrido [1,2‐d][1,4]oxazepin‐5(4H)‐one, 1,6,11,11a‐tetrahydro [1,4]‐oxazino [4,3‐b]isoquinolin‐4(3H)‐one and of hexahydropyrido [2,1‐c][1,4]thiazin‐4(3H)‐one are also discussed. cis‐6,9a‐H‐6‐Methyl‐hexahydropyrido[2,1‐c][1,4]oxazin‐4(3H)‐one is shown to exist in a conformation containing a deformed perhydropyridine ring.

Synthesis of methyl d-mannofufanosides and of 5-O-methyl-d-mannose

Kuhn methylation of 2,3:5,6-di-O-isopropylidene-d-mannofuranose affords a mixture of methyl 2,3:5,6-di-O-isopropylidene-α-d-mannofuranoside and methyl 2,3:5,6-di-O-isopropylidene-β-d-mannofuranoside, in the ratio 99:1. Treatment of the sodio derivative of the di-acetal with methyl iodide gave the same products, but the ratio was reversed and was 10:1 in favour of the β-d-anomer. Convenient procedures for the synthesis of methyl α-d-mannofuranoside and methyl β-d-mannofuranoside from the corresponding di-acetals are described, and a synthesis of 5-O-methyl-d-mannose is also presented.

New Compounds: Derivatives of Some Imido Compounds Likely to Possess Therapeutic Activity

The synthesis of certain N-alkylated derivatives of hydantoin, barbituric acid, succinimide, and glutarimide is described. The alkylation was achieved either by direct fusion of the imide with the halo compound in the presence of anhydrous potassium carbonate or by heating the sodio derivative of the imide with the halo compound in the presence of dimethylformamide as solvent. In the case of barbiturates, a dialkylated product was always obtained even when equimolecular amounts of reactants were used.

Synthetic investigations in the sesamin group

Ethylα-bromovinylacetate (VII) was condensed with the sodio derivative of ethyl piperonoylacetate (VIII) to give diethylα-vinyl-α′-piperonoylsuccinate (IX). The latter on reduction with lithium aluminium hydride furnished the triol (X), which underwent smooth cyclisation with 1% ethanolic hydrogen chloride to 2-(3′, 4′-methylenedioxyphenyl)-hydroxymethyl-4-vinyltetrahydrofuran (XIa). The structure of XIa was established by Oppenauer oxidation to an aldehyde. Ozonolysis of XIa afforded samin (I).

Preparation and characterization of sodium cellulosates

AbstractA method of preparing sodium cellulosates by an exchange reaction between cellulose and sodium alkoxide in alcohol medium is proposed. Anhydrous systems of sodium methoxide in methanol and sodium n‐butoxide in n‐butanol were used to treat cotton and viscose rayon celluloses to form sodium alcoholates of cellulose. It is shown that alcohols used as extraction solvents in the purification of the reaction products must be of low acidity, such as branched chain alcohols, since straight chain alcohols of relatively high acidity are shown to cause destruction of the sodio derivatives. The distribution of sodium in the products was found indirectly by methylating the sodio derivatives in pure methyl iodide and determining the distribution of methoxyl groups by paper chromatographic techniques. It was indicated that the sodium substituent was distributed in the various sodium cellulosates in a somewhat random arrangement. Glucose, mono‐O‐methyl glucose, di‐O‐methyl glucose, and tri‐O‐methyl glucose constituted the distribution products. The mono‐O‐methyl glucose fractions were further separated, to disclose the presence of the 2,3, and 6 isomers. The degree of substitution (DS) found for the sodium cellulosates ranged from 0.52 to 1.72.

Reactions of some dicarbonyl compounds

The reactions of some halogeno keto-esters and the sodio derivatives of β-dicarbonyl compounds have been investigated.

Isomerism of Derivatives of Cyclohexane

BOTH 4-methylcyclohexane-l-carboxy-l-succinic acid and 3-methylcyclohexane-l-carboxy-l-succinic acid, synthesized by condensation of ethyl bromoacetate with the sodio derivatives of the dicyano esters prepared by Higson and Thorpe's method1, have been isolated in two forms ; there being no indication of isomerism connected with multiplanar forms2. This method provides a satisfactory synthesis of the tricarballylic acids derived from cyclic ketones, and the low yield of -dimethyltricarballylic acid obtained from acetone3 can be raised to nearly 30 per cent by suitable modification of the method. The conversion of the tricarballylic derivatives into the corresponding aconitic acids is being investigated.