Ethyl Oxalyl Chloride Research Articles

Synthesis of functionalized phenylphosphinic acid resins through Michael reaction: Part II. Resins with multidentate ligands

Functionalized resins, containing substituted phenylphosphinic acid ligands, were obtained by the reaction of styrene–divinylbenzene copolymer (2 wt.% of crosslinker, expanded gel structure) bearing phenylphosphinic acid groups with trimethylchlorosilane and then with an appropriate electrophile. Reactions were carried out with ethyl oxalylchloride, ethyl bromopyruvate and ethyl-4-chloroacetoacetate and resulted in resins with multidentate ligands, having acid capacities of 3.57, 3.86 and 3.33 mmol/g, respectively. These resins, obtained in 66–93% yield, were used in the removal of Cu(II), Cd(II), Ni(II), Zn(II), Mg(II) and Ca(II) from nitric acid solutions and their performance compared to the performance of the parent, phenylphosphinic acid resin. It was found that resin 1, obtained in the reaction of phenylphosphinic resin with ethyl oxalylchloride, has the highest affinity towards all of the above cations, whereas the remaining two resins performed similarly to the phenylphosphinic acid resin. New, functionalized resins were also used in an ester form for the removal of Au(III), Cu(II), Fe(III) and Ag(I) chlorocomplexes from hydrochloric acid solutions of various concentrations. It was found that resins in an ester form are able to selectively complex tetrachloroaurate from 0.5 to 6.0 M HCl. For example, ester form of resin 3 ( P=1.78, OH=0.64, %=70.30), removes the above mentioned chlorocomplexes from 1 M HCl solution. Log K d values are 4.08, 0.95, 0.97 and 1.46 for Au(III), Cu(II), Fe(III) and Ag(I), respectively.

Direct synthesis of Fmoc-protected amino acids using organozinc chemistry: application to polymethoxylated phenylalanines and 4-oxoamino acids†

The new N-Fmoc 3-iodoalanine tert-butyl ester derived organozinc reagent 1, obtained in 7 steps from optically pure L-serine, was coupled to a range of electrophiles under palladium catalysis to give substituted phenylalanines and 4-oxoamino acids in variable yields (21–59%). Transformation into the organocopper reagent 13 allowed coupling with allyl chloride and ethyl oxalyl chloride. Removal of the tert-butyl group gives Fmoc-protected amino acids (63–95%), suitable for use in automated solid phase peptide synthesis.

STEREOSELECTIVE SYNTHESIS OF MONOFLUORO-OLEFINS FROM DIISOPROPYL (CARBOETHOXYFLUORO-METHYL)PHOSPHONATE

Treatment of ethyl oxalyl chloride or methyl oxalyl chloride with lithium diisopropyl(carboethoxyfluoromethyl)phosphonate[(i-PrO)2P(O)CFCO2Et]−Li+ 2 followed by in siru nucle-ophilic addition with methylmagnesium iodide or vinyl magnesium bromide affords with exclusive E-stereoselectivity formation of diethyl-2-fluoro-3-methyl fumarate (CH3)(C02Et)C˭CFCO2Et 4 or 75% of the E-isomer of a-fluoro-P-vinyl-a,P-unsaturated diester (E,Z)-(CH2˭CH)(CO2C2H5)C˭CFCO2Et 5, respectively. However, direct reaction of ethyl pyruvate with 2 gives the fluoro-olefin (CH3)(CO2Et)C˭CFCO2Et 4 with 79% E-stere-oselectivity. The E/Zratio of (CH2˭CH)(CO2Et)C˭CFCO2Et 5 depends on the HMFT or DMPU cosolvents present in the reaction mixture.

DiethylN,N'-(Naphthalene-1,8-diyl)dioxamate

The reaction of ethyloxalyl chloride and naphthalene-1,8-diamine in refluxing tetrahydrofuran yielded the title compound, C18H18N2O6. The crystal structure analysis reveals a molecule with one oxamate substitutent nearly coplanar with the aromatic naphthalene system, while the second is strongly twisted with respect to the naphthalene system. Three strong intra­molecular hydrogen bonds are observed, one in each oxamic acid ethyl ester group and one linking the two substitutents. Symmetry-related molecules are connected by a fourth intermolecular hydrogen bond.

Isolation and Characterization of intermediate in the Synthesis of α‐Fluorodiesters

AbstractThe anion [(EtO)2P(O)CFCO2Et]−Li+, pregenerated from its precursor diethyl (carboethoxyfluoromethyl)phosphonate (EtO)2P(O)CFHCO2Et and n‐butyllithium, was added via syringe to a THF solution of ethyl oxaiyl chloride to yield an acylated phosphonate (EtO)2P(O)CF(COCO2Et)CO2Et. In situ reaction with Grignard reagents RMgX produces the α‐fluorodiesters (E,Z)‐R(CO2Et)C=CFCO2Et in good yields. In contrast, addition of ethyl oxalyl chloride to a THF solution of diethyl (carboethoxyfluoromethyl)phosphonate anion gives an isolated intermediate (EtO)2P(O)CFCO2Et(CO2Et)C=CFCO2Et. Subsequent reaction of this isolated intermediate with Grignard reagents also affords a one‐pot synthesis of the α‐fluorodiesters with high E‐stereoselectivity. The E‐stereoselectivity increases when HMPT or DMPU is used as a cosolvent in the preparation of diethyl 2‐fluoro‐3‐phenylfumarate (E,Z)‐Ph(CO2Et)C=CFCO2Et.

Polycarbonyl heterocycles, Part IX 1: Synthesis of thiophene-2,3-dione derivatives and their transformation to pyrrolo[3,2- c]pyridine systems

Thiophene-2,3-dione derivatives 2 were prepared in the reaction of β-aminovinylthioamides 1 with ethyl oxalyl chloride. Treatment of compounds 2b,c with malonodinitrile led to the ring transformation of the thiophene-2,3-dione system to pyrrolo[3,2- c]pyridine derivatives 4b,c.

Synthesis of deterium labeled plant ethylene precursor

AbstractSynthetic methods for the preparation of β‐deuterium labeled 2‐keto‐4‐methylbutyric acid were investigated. Vinyl chloride was first reacted with the ethyl oxalyl chloride moiety using aluminum chloride as condensing agent and the addition of methyl mercaptan followed. Deuterium labeling was achieved by using NaBD4 reduction in pyridine.

ChemInform Abstract: Synthesis of Dienic α‐Ketoesters by Friedel‐Crafts Reaction of Ethyl Oxalyl Chloride with Tricarbonyl Iron Complexes of E‐ and Z‐ Substituted Acyclic Dienes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of dienic α-ketoesters by Friedel-Crafts reaction of ethyl oxalyl chloride with tricarbonyl iron complexes of E- and Z- substituted acyclic dienes

Tricarbonyl iron coordinated acyclic dienes react with ethyl oxalyl chloride|AlCl 3 to E- dienic α-ketoester complexes. This allows a rapid synthesis of such dienes by decomplexation. Not only E- alkyl-substituted but also Z-substituted dienes can be functionalized this way, whereas Z-dienic α-ketoester complexes can be obtained by acid catalyzed E → Z isomerization.

ChemInform Abstract: Reaction of a Serine‐Derived Organozinc Reagent with Chloroformates and Ethyl Oxalyl Chloride Under Palladium Catalysis. Preparation of Protected (2S,6S)‐4‐Oxo‐2,6‐diaminopimelic Acid and (2S)‐4‐Oxoglutamic Acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reaction of a serine-derived organozinc reagent with chloroformates and ethyl oxalyl chloride under palladium catalysis. Preparation of protected (2S, 6S)-4-oxo-2,6-diaminopimelic acid and (2S)-4-oxoglutamic acid

Organozinc reagent 1 reacts with phenyl chloroformate under palladium catalysis to give the protected 4-oxo-2,6-diaminopimelic acid derivative 3, derived by formal displacement of both chloride and phenoxide; the symmetrical ketone 3, together with protected 4-oxoglutamic acid 10, are formed when ethyl oxalyl chloride is used as substrate.

Preparation and Reaction of Cyclic Oxalate of Diols

Abstract Cyclic oxalates were efficiently prepared by the reaction of diols with ethyl oxalyl chloride in the presence of triethylamine. They were stable under acidic conditions but cleaved to diols under basic conditions.

ChemInform Abstract: Synthesis of the Ethyl Oxalyl Tetracarbonyl Iron Anion ((CO)4FeCOCO2Et)‐, Its Methylation at the Metal into (CO)4Fe(Me)(COCO2Et) and Further Carbon‐Carbon Coupling into Ethyl Pyruvate.

AbstractCoupling of the iron carbonyl complex (I) with ethyl oxalyl chloride (II) and subsequent metathesis with bis(triphenylphosphoranylidene)ammonium chloride (IV) produce the salt (V) which is methylated with methyl triflate (VI) at a low temperature to yield the methyliron complex (VII).

ChemInform Abstract: Magnetism of Alternating Bimetallic Chains: Application to MnCu(obzp)(H2O)3·H2O (obzp: Oxamido‐N‐benzoato‐N′‐propionato).

AbstractThe title complex (I) and its oxamido‐N‐phenolato‐N'‐propionato analogue are prepared in five steps starting from ethyl oxalyl chloride and anthranilic acid or 2‐aminophenol, respectively.

A facile synthesis of monodisperse carboxylated polystyrene and derivatives

AbstractA method is presented for the synthesis of monodisperse carboxylated polystyrene (3) and derivatives by a Friedel‐Crafts acylation of monodisperse polystyrene with ethyl oxalyl chloride (1). Saponification of the resulting α‐keto ester yields the randomly carboxylated copolymer, whose structure was confirmed by NMR and infrared spectra. Viscosity measurements and gel permeation chromatography showed that no chain cleavage operated during the process of functionalization. The value of the technique lies in its simplicity of execution and the availability of starting materials.

Oxamates derived from 5‐aminopyrazoles

AbstractSeveral oxamates were prepared from ethyl oxalyl chloride and 5‐amino‐4‐cyanopyrazoles substituted in the 1‐position with aryl, aroyl and arylsulfonyl groups. Both aroyl and arylsulfonyl groups suffered chloride‐induced cleavage during this process. The synthesis of 7‐(6‐chloro‐3‐pyridazinyl)‐7H‐pyrazolo[3,4‐d]‐1,2,3‐tri‐azin‐4(3H)‐one (11) and its reaction with methanol to give 1‐(6‐chloro‐3‐pyridazinyl)‐5‐methoxy‐1H‐pyrazole‐4‐carboxamide (12) are also reported. A mechanism for this interesting transformation is presented.

ChemInform Abstract: N‐(4‐SUBSTITUTED‐THIAZOLYL)OXAMIC ACID DERIVATIVES, NEW SERIES OF POTENT, ORALLY ACTIVE ANTIALLERGY AGENTS

AbstractDie aus den Verbindungen (I) oder (IV) zugänglichen Amino‐thiazole (III) werden in die Ester (V) übergeführt, aus denen man die Carbonsäuren (VI) bzw. Amide (VII) erhält.

N-(4-substituted-thiazolyl)oxamic acid derivatives, a new series of potent, orally active antiallergy agents.

A series of N-(4-substituted-thiazolyl)oxamic acid derivatives were synthesized and tested for antiallergy activity in the rat PCA model. These compounds were conveniently prepared by treatment of the appropriate acetophenone with thiourea and iodine or by reaction of the chloroacetylbenzene with thiourea to give the corresponding aminothiazoles; subsequent condensation with ethyloxalyl chloride gave the thiazolyloxamates. Many of the analogues showed a 50% inhibition at less than 2 mg/kg po or less than 0.4 mg/kg iv and were significantly more potent than disodium cromoglycate, which in the rat PCA model is orally inactive and gives a 50% inhibition at 1.2 mg/kg iv. Hydrolysis of the oxamates generally resulted in enhanced activities, while substitution of the phenyl ring with a variety of substituents (e.g., 4-F, 4-OEt, and 4-NHCOCH3) did not significantly enhance the activity of the unsubstituted phenyl derivative. One of the ethanolamine salts, N-[4-(1,4-benzodioxan-6-yl)-2-thiazolyl]oxamic acid ethanolamine salt (61, PRH-836-EA), has been selected for further pharmacological evaluation.

Bicyclic heterocycles with nitrogen at the ring junction. Part 2. Application of the Dakin–West reaction to the synthesis of imidazo[5,1-f]-1,2,4-triazin-4(3H)-ones

A series of novel acylamino α-keto-esters (4) have been prepared via a Dakin–West reaction of acylated a-aminoacids and ethyl oxalyl chloride. Their use in a general synthesis of imidazo[5,1-f]-1,2,4-triazin-4(3H)-ones (7) is described. The conversion of the imidazotriazinones into the corresponding imidazo[5,1-f]-1,2,4-triazines (20) and their 3,4-dihydro-derivatives (19) are also reported.

Synthesis of 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives

AbstractSeveral new 3‐arylsulfonylmethyl‐1,2,4‐oxadiazole‐5‐carboxylic acid derivatives have been synthesized. A typical example, 3‐[(4‐chlorophenylsulfonyl)methyl]‐1,2,4‐oxadiazole‐5‐carboxylic acid ethyl ester (2c), was prepared from the reaction of 2‐(4‐chlorophenylsulfonyl)acetamide oxime (1c) with ethyl oxalyl chloride. The hydrazide derivative (3f) showed antihypertensive activity in rats. Various structural modifications to improve activity are discussed.