Enzymatic hydrolysis of long-chainN-heterocyclic fatty esters

Incubation of a 1-pyrroline ester [viz. methyl 8-(5-hexyl-1-pyrroline-2-yl)octanoate,1] with bakers' yeast (Saccharomyces cerevisiae) gave the corresponding free fatty acid (1a, 52%). The C=N bond of the 1-pyrroline was not reduced by the yeast. Complete hydrolysis of compound1 was successful using lipase ofCandida cylindracea (CCL) or Lipolase (Rhizomucor miehei) under stirred or ultrasound condition. Fatty esters containing a pyrrolidine [viz. methyl 8-(cis/trans-5-hexyl-pyrrolidine-2-) octanoate,2] orN-methyl pyrrolidine [viz. methyl 8-(cis-5-hexyl-N-methyl-pyrrolidine-2-)octanoate,3] system in the alkyl chain were not hydrolyzed by either CCL or Lipolase, unless conducted in an ultrasonic bath. The hydrolytic activities of the enzymes appeared to be strongly affected by the stereochemistry of theN-heterocyclic ring system. Chemical hydrolysis of compounds1–3 gave the corresponding fatty acidN-HCl salts.     

A novel method for the introduction of a methyl group into the furan ring of a 2,5-disubstituted C18 furanoid fatty estervia a malonic acid function

Furan ring opening with benzohydroxamic acid of methyl 9,12-epoxy-9,11-octadecadienoate gave a mixture of positional isomers of conjugated methyl 3-phenyl-1,4,2-dioxazolyl C₁₈-enone esters 6a,6b. Michael addition of diethyl malonate anion to the conjugated enone system of 6a,6b furnished the corresponding malonyl intermediates 7a,7b, which upon removal of the dioxazole ring by hydrolysis gave methyl 10- and 11-dicarbethoxymethyl-9,12-dioxooctadecanoate 8a,8b. Cyclization of the latter gave the trisubstituted C₁₈ furanoid fatty esters 9a,9b, containing the malonate ester function at the 3-/4-position of the furan ring. Base hydrolysis of compounds 9a,9b gave the corresponding tricarboxylic acid derivatives 10a,10b, which were esterified to the trimethyl esters 11a,11b in BF₃/MeOH. When a mixture of 9a,9b was refluxed with Na₂CO₃/MeOH, hydrolysis of the malonate ester function was followed by decarboxylation to yield a-CH₂COOH substituent at the 3-/4-position of the furan ring (12a, 12b). Esterification of the latter with BF₃/MeOH gave the corresponding methyl diester derivatives 13a,13b. When a mixture of tricarboxylic acids 10a,10b was heated at 160–180°C for 6 hr, exhaustive decarboxylation of malonic acid function furnished a methyl group at the 3-/4-position of the furan nucleus. Esterification of the decarboxylated product gave a mixture of trisubstituted furanoid compounds 14a,14b (overall yield 28%). The procedure constitutes a novel method for the introduction of a methyl groupvia a malonic acid group to the 3-/4-position of the furan ring of a 2,5-disubstituted C₁₈ furanoid fatty ester.     

Synthesis of novel tri- and tetrasubstituted C<Subscript>18</Subscript> furan fatty esters

A methylene-interrupted C₁₈ keto-acetylenic fatty ester (methyl 12-oxo-9-octadecynoate) was obtained from methyl ricinoleate by bromination-dehydrobromination followed by oxidation. Reaction of methyl 12-oxo-9-octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide furnished methyl 8-[5-hexyl-3-allyl-furan-2-yl]-octanoate (1, 56%) or methyl 8-[5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (2, 55%). Reaction of methyl 12-oxo-11-chloro-or 11-fluoro-9-octadeyynoate (prepared from methyl santalbate-methyl 11-E-9-octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (3, 50%) or methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (4, 50%), respectively. And when methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide, the reaction yielded tetrasubstituted C₁₈ furan derivatives, viz, methyl 8-(3-allyl-4-chloro-5-hexyl-furan-2-yl)-octanoate (5, 54%), methyl 8-[4-chloro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl)-octanoate (6, 54%), methyl 8-(3-allyl-4-fluoro-5-hexyl-furan-2-yl]-octanoate (7, 10%), and methyl 8-[4-fluoro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the ¹³C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.     

Elucidation of cyclic fatty acid monomer structures. Cyclic and bicyclic ring sizes and double bond position and configuration

Gas chromatography (GC)-electron ionization mass spectrometry of 2-alkenyl-4,4-dimethyl-oxazoline derivatives was used to confirm the identities of a complex mixture of C₁₈ diunsaturated cyclic fatty acid monomers (CFAMs) that were isolated from heated flaxseed (linseed) oil. The positions of double bonds and 1,2-disubstituted unsaturated 5- and 6-membered rings along the fatty acid hydrocarbon chains were established by this method. The oxazoline spectra exhibited a homologous ion series with a pattern of peaks that were 14 u (u=atomic mass unit) apart but interrupted when a double bond (12-u mass interval) or a ring was present along the fatty acid chain. The identity and location of a ring were indicated by a large interval of 68, 82, 66, 80, 78, or 120 u for a saturated 5- or 6-membered ring, monounsaturated 5- or 6-membered ring, diunsaturated 6-membered ring, or monounsaturated bicyclic ring system (fused 5- and 6-membered rings), respectively. The double bond configuration for the methyl ester derivatives of these CFAMs was established by GC-matrix isolation-Fourier transform infrared spectroscopy. The elucidated alkenyl structures at C₂ in diunsaturated 2-[alkenyl]-4,4-dimethyloxazolines were 8-(2-but-trans-1-enyl-cyclopentenyl)octyl, 9-(2-propyl-cyclopentenyl)non-rans-8-enyl, 9-(2-propyl-cyclopentenyl)non-cis-7-enyl, 8-(2-but-cis-1-enyl-cyclopentenyl)ocytl, 9-(2-propylcyclopentenyl)non-cis-8-enyl, 8-(2-propyl-cyclohex-cis-4-enyl)oct-trans-7-enyl, 8-(prop-trans-1-enyl-cyclohex-cis-4-enyl)ocytl, and 8-(2-propylcyclohexa-cis,cis-3,5-dienyl)octyl. Physical science aide, 1991–1992; currently a medical student at the University of Maryland, Baltimore, MD.     

Synthesis of trisubstituted C18 pyrrole fatty ester derivatives

Reaction of methyl 10(11)-dicarbethoxymethyl-9,12-dioxooctadecanoate (1a,1b) with ammonium acetate furnished a mixture of positional isomers of a pyrrole derivative, methyl 9,12-imino-10(11)-dicarbethoxymethyl-9,11-octadecadienoate (2a,2b). Decarboxylation of the mixture of compounds 2a,2b with sodium carbonate in aqueous methanol yielded a mixture of compounds 3a,3b containing a CH₂COOCH₃ group at the 3- or 4-position of the pyrrole ring after esterification. Heating of the hydrolyzed mixture of compounds 3a,3b at 180°C for 1 h gave the desired trisubstituted pyrrole derivatives, methyl 9,12-imino-10(11)-methyl-9,11-octadecadienoate (4a,4b), containing a methyl group at the 3- or 4-position of the pyrrole nucleus. The structures of the products and intermediates were confirmed by infrared, and by¹H and¹³C nuclear magnetic resonance spectroscopy.     

Ultrasound in fatty acid chemistry: Synthesis of a 1-pyrroline fatty acid ester isomer from methyl ricinoleate

A novel 1-pyrroline fatty acid ester isomer [viz. 8-(5-hexyl-1-pyrrolin-2-yl)octanoate] has been synthesized from methyl ricinoleate by two routes with an overall yield of 42 and 30%, respectively. Most of the reactions are carried out under concomitant ultrasonic irradiation (20 KHz,ca. 53 watts/cm²). Under such a reaction condition, the reaction time is considerably shortened, and product yields are high. Dehydrobromination under concomitant ultrasonic irradiation of methyl 9,10-dibromo-12-hydroxyoctadecanoate with KOH in EtOH furnishes methyl 12-hydroxy-9-octadecynoate (66%) within 15 min. Hydration of the latter under ultrasound with mercury(II)acetate in aqueous tetrahydrofuran yields exclusively methyl 12-hydroxy-9-oxo-octadecanoate (95%) in 30 min. The hydroxy group in the latter compound is transformed to the azido functionvia the mesylate, and treatment of the azido-oxo intermediate (methyl 12-azido-9-oxooctadecanoate) with Ph₃P under ultrasonic irradiation furnishes the requisite 1-pyrroline fatty acid ester (77%). The same azido-oxo intermediate has also been obtained by the oxidation of methyl 12-azido-9-cis-octadecenoate using benzoquinone and a catalytic amount of Pd(II)chloride in aqueous tetrahydrofuran under concomitant ultrasonic irradiation (90 min) to give the product in 45% yield. The latter reaction does not take place even under prolonged silent stirring of the reaction mixture.     

Reaction of mono-epoxidized conjugated linoleic acid ester with boron trifluoride etherate complex

The reaction of methyl 11, 12-E-epoxy-9Z-octadecenoate (1) with boron trifluoride etherate furnished a mixture of methyl 12-oxo-10E-octadecenoate (3a) and methyl 11-oxo-9E-octadecenoate (3b) in 66% yield. Methyl 9, 10-Z-epoxy-11 E-octadecenoate (2) with boron trifluoride etherate furnished a mixture of methyl 9-oxo-10 E-octadecenoate (4a, 45%) and methyl 10-oxo-11 E-octadecenoate (4b, 19%). A plausible mechanism is proposed for these reactions, which involves the attack on the epoxy ring system by BF₃, followed by deprotonation, oxo formation, and double bond migration to give a mixture of two positional α,β-unsaturated C₁₈ enone ester derivatives (3a/3b, 4a/4b). The structures of these C₁₈ enone ester derivatives (3a/3b, 4a/4b) were identified by a combination of NMR spectroscopic and mass spectrometric analyses.     

Hydrogen sulfide adducts of methyl oleate and linoleate

Sulfur compounds derived from photochemical addition of hydrogen sulfide to methyl oleate and linoleate were separated by preparative gas chromatography. The major compounds were investigated by NMR, mass and IR spectroscopy and by elemental analysis. The primary product of the methyl oleate reaction was methyl 9(10)-mercaptostearate. Gas chromatograms of the product from methyl linoleate showed four principal peaks. From mass spectra and NMR data, we identified methyl 9-(2-pentyl-1-thiolan-5-yl)nonanoate, methyl 8-(2-hexyl-1-thiolan-5-yl)octanoate and methyl 9-(3-hexyl-1,2-dithiolan-5-yl)nonanoate. Evidence for the formation of methyl mercapto-octadecenoates and methyl dimercaptostearates was also obtained. ARS, USDA.     

Ethylene adduct of conjugated octadecadienoic acids: I. Peracid oxidation products

8-(4-n-Hexylcyclohex-2-enyl)octanoic acid obtained by the addition of ethylene totrans,trans-9,11-octadecadienoic acid was treated with 28% hydrogen peroxide in acetic or formic acid to give the hydroxyacetoxy or-formoxy derivative. Saponification of the hydroxyacetoxy derivative yielded two crystalline glycols. The hydroxyformoxy fatty acid was converted in one step either to the glycol ester, methyl 8-(4-n-hexyl-2,3-dihydroxycyclohexyl)octanoate, by reaction with anhydrous hydrochloric acid in methanol or to the acetone derivative of the glycol ester by treatment with dimethoxypropane and anhydrous hydrochloric acid in methanol. Epoxidation of the C₂₀ cyclohexene fatty methyl ester gave the oxirane derivative. A ring opening reaction of the diol acid with periodic acid yielded 9,12-diformylstearic acid. Presented in part at the AOCS-AACC Meeting, Washington, D.C., April 1968. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Hydrogen sulfide adducts of methyltrans,trans- 9,11-octadecadienoate

Hydrogen sulfide was added to methyltrans, trans- 9,11-octadecadienoate in benzene solution at 25 C with ultraviolet radiation. GC-MS and GLC analysis of the reaction product showed the presence of methyl oleate, methyl stearate, geometric isomers of methyl 9,11-octadecadienoate, methyl 9,12-epoxy-octadeca-9, 11-dienoate, an unknown compound with an apparent molecular weight of 306, methyl 8-(2′,5′-hexylthienyl) octanoate, an unidentified sul-fur ] containing C₁₈ ester with an apparent molecular weight of 326, methyl 9,12-epithiostearate, an adduct of methyltrans,trans- 9,11-octadecadienoate and ben-zene [bicyclo (4.4.0)-deca-2,5,7-triene-l-(Ω-carboxy-methyl heptyl)-4 hexyl] and a probable mixture of methyl 9,11-epidithiostearate, methyl 9,12-epidithio-stearate, and methyl 10,12-epidithiostearate.     

5-Pyrenylidene-hydantoin, 2-thiohydantoin derivatives: synthesis,S- and N-alkylation

5-Pyrenylidene-2-thiohydantoin derivatives 2a–d were prepared by condensation of pyrene-1-carboxaldehyde with 2-thiohydantoin derivatives. Compounds 2a,b undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 3a,b respectively. S- and N-monoalkyl-5-pyrenylidene-hydantoin derivatives 5a,b and 6a,b were prepared by reaction of 5-pyrenylidene-2-thiohydantoin sodium salts with 1,3-dioxolan-methylsulfate derivatives. Deprotection of the products afforded 5-pyrenylidene-hydantoin (7), S- and N-dihydroxy derivatives 8a,b and 9a,b respectively. Reaction of 2a with methyl iodide afforded the corresponding S-methyl derivative 10, which reacted with secondary amines such as morpholine and piperidine afforded the glycocymidine derivatives 11a,b. Reaction of 2a with (2,3,4,6-tetra-O-acetyl-α-? D-glucopyranosyl)bromide afforded a mixture of S- and N-glucoside derivatives 12 and 13 respectively. Deprotection of 12 afforded compound 7, while deprotection of 13 furnished 5-Pyrenylidene-3-? D-glucopyranosyl-2-thiohydantoin (14). Reaction of 7 with propargyl chloride in DMF afforded the monoalkynyl- and bis-alkynyl-hydantoin derivatives 15 and 16, respectively. Reaction of 15 with p-bromophenyl-ether derivative 17 yielded the bis-alkynyl derivative 18.     

Rapid determination of double bond configuration and position along the hydrocarbon chain in cyclic fatty acid monomers

This study reports the structural elucidation of diunsaturated 5- or 6-membered ring cyclic fatty acid monomers (CFAM) isolated from heated flaxseed oil by complementary gas chromatography (GC)-mass spectrometry (MS) and GC-matrix isolation-Fourier transform infrared spectroscopy (MI-FTIR). Infrared measurements of CFAM were carried out on methyl ester derivatives as well-resolved chromatograms were obtained on a polar 100% cyanopropyl polysiloxane capillary GC column. By contrast, electron ionization MS of methyl ester derivatives was of limited value because of double bond migration during the ionization process in the mass spectrometer. This communication reports definitive MS fragmentation patterns that can confirm ring position and double bond position along the fatty acid chain in 1,2-disubstituted CFAM determined as 2-alkenyl-4,4-dimethyloxazoline derivatives. Double bond configuration (cis, trans, or conjugatedcis,cis) in CFAM was confirmed by GC-MI-FTIR. The presence of CFAM, degradation products found in used frying oils, is a potential source of dietary toxicity. This work was presented in part at the 84th American Oil Chemists' Society Annual Meeting held in Anaheim, CA, in April 1993.     

Effect of α-tocopherol on the volatile thermal decomposition products of methyl linoleate hydroperoxides

α-Tocopherol and 1,4-cyclohexadiene were tested for their effect on the thermal decomposition of methyl linoleate hydroperoxide isomers. The volatiles generated by thermolysis in the injector port of a gas chromatograph at 180°C were analyzed by capillary gas chromatography. In the presence of either α-tocopherol or 1,4-cyclohexadiene, which are effective donors of hydrogen by radical abstraction, volatile formation decreased in all tests, and significant shifts were observed in the relative distribution of products in certain hydroperoxide samples. When an isomeric mixture of methyl linoleate hydroperoxides (cis, trans andtrans, trans 9- and 13-hydroperoxides) was decomposed by heat, the presence of α-tocopherol and 1,4-cyclohexadiene caused the relative amounts of pentane and methyl octanoate to decrease and hexanal and methyl 9-oxononanoate to increase. A similar effect of α-tocopherol was observed on the distribution of volatiles formed from a mixture of thetrans,trans 9- and 13-hydroperoxides. This effect of α-tocopherol was, however, insignificant with purecis,trans 13-hydroperoxide of methyl linoleate. The decrease in total volatiles with the hydrogen donor compounds, α-tocopherol and 1,4-cyclohexadiene, indicates a suppression of homolytic β-scission of the hydroperoxides, resulting in a change in relative distribution of volatiles. The increase in hexanal and methyl 9-oxononanoate at the expense of pentane and methyl octanoate in the presence of hydrogen donor compounds supports the presence of a heat-catalyzed heterolytic cleavage (also known as Hock cleavage), which seems to mainly affect thetrans,trans isomers of linoleate hydroperoxides.     

Structural analysis of oxidation products of urofuran acid by hypochlorous acid

The oxidation of urofuran acid derivatives (1–2) by hypochlorous acid (HOCl) was investigated with the goal to possibly simplify the detection of their metabolites in biological materials. The oxidation products of 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (1) were obtained as an isomeric mixture and confirmed to exist ascis (3a) andtrans (3b) isomers, based on their¹³C nuclear magnetic resonance (NMR) spectra. Similarly, the products of 5-H substituted acid 2 obtained by oxidation with HOCl were identified as 4a and 4b by¹³C and¹H NMR which indicated the presence ofcis andtrans hemiacetal hydrogens at C-5 in a ratio of 2.11∶1. The oxidation was found to proceed in a manner different from that of the F-acid, because of the presence of the electron withdrawing COOCH₃ group at C-3 which favored the nucleophilic attack on the carbonyl group to affordcis- andtrans-2,5-dihydroxy-2,5-dihydrofurans (3a−b, 4a−b).     

Efficient and Selective Synthesis of E‐Vinylamines via Tungsten(0)‐Catalyzed Hydroamination of Terminal Alkynes

The hydroamination of terminal alkynes (RCCH=phenylacetylene, 4‐methylphenylacetylene, 4‐fluorophenylacetylene, 1‐hexyne, methyl 2‐propynyl ether, prop‐2‐yn‐1‐ol) with secondary amines (piperidine, pyrrolidine, morpholine, piperazine, methylpiperazine, 4‐methylpiperidine and 3‐methylpiperidine) was achieved in high yield (up to 99%), regioselectivity (only anti‐Markovnikov product) and stereoselectivity (only E‐isomers) within a maximum of 5 h in reactions catalyzed by the tungsten tetracarbonyl complex cis‐[W(CO)₄(piperidine)₂] at 90 °C without any additional solvent.

     

Bis-(1-chlor-3-phenoxy-prop-2-yl)-sulfane – Nucleophile Substitution und Regiochemie,Diastereomerentrennung und -zuordnung. Synthese diastereomerenreiner Trithiacyclen

Bis-(1-chloro-3-phenoxy-prop-2-yl)-sulfanes – Nucleophilic Displacement and Regiochemistry. Separation and Assignment of Diastereomers. Synthesis of Diastereomerically Pure Trithiacycles The title compounds 1 were substituted by a series of O-, N- and S-nucleophiles (H₂O solvolysis, AgOAc, NaN₃, KSCN, NaSPh, thiourea). A strong tendency to β-elimination of HCl depending on the kind of the attacking nucleophile was found. In most cases no regioisomerization could be detected in the isolated products of the nucleophilic displacement. Best results were obtained with sulfur nucleophiles. The separation of the diastereomeric mixture of the p-kresyl derivative 1b into the individual diastereomers 1bA and 1bB in a preparative scale was achieved. These 3-thia-1,5-dichlorides and several products of substitution could be assigned to the meso- or (±)-form by examination of the stereochemistry and symmetry of the corresponding sulfoxides. The 1,5-dimercapto derivatives 8 are convenient as structural units for the synthesis of diastereomerically pure cis- or trans-disubstituted trithiacycles e.g. 15bA , 15bB . The (±)-form of the 4,6-disubstituted 2,5,8-trithia[9]-(2,6)-pyridinophane 16bA was characterized by X-ray crystal structure determination.     

Oxidation reactions of acetylenic fatty esters with selenium dioxide/tert-butyl hydroperoxide

Reaction of methyl undec-10-ynoate (1) with selenium dioxide/tert-butyl hydroperoxide (TBHP) in aqueous dioxane gave methyl 9-oxo-undec-10-ynoate (2, 9%) and 9-hydroxy-undec-10-ynoate (3, 60%), while methyl octadec-9-ynoate (4) yielded mixtures of positional isomers of mono-keto (viz. methyl 8-oxo- and 11-oxo-octadec-9-ynoate, 5, 5%), hydroxy-keto (viz. methyl 8-hydroxy-11-oxo-and 11-hydroxy-8-oxo-octadec-9-ynoate, 6, 10%), and dihydroxy (viz. methyl 8,11-dihydroxy-octadec-9-ynoate, 7, 24%) derivatives. Similar treatment of a conjugated diacetylenic fatty ester (methyl octadeca-6,8-diynoate, 8) furnished a mixture of methyl 5-oxo-and 10-oxo-octadeca-6,8-diynoate (9, 12%) and a complex mixture of very polar products. Reaction of methyl octadec-11E-en-9-ynoate (methyl santalbate) (10) with selenium dioxide/TBHP in aqueous dioxane gave exclusively a mixture of regiospecific products, viz. methyl 8-oxo-octadec-11(E) Z-en-9-ynoate (11, 6%) and methyl 8-hydroxy-octadec-11 E-en-9-ynoate (12, 70%). The structures of the various products were determined by a combination of spectroscopic and mass spectral analyses.     

Synthesis of 2H‐Thiopyrans by Rhodium(II) Acetate‐Catalyzed Reaction of 4‐Amino‐2,5‐dihydro‐3‐thiophenecarbonitriles with α‐Diazocarbonyl Compounds. Part 1

4‐Amino‐2,5‐dihydro‐3‐thiophenecarbonitriles 1 reacted with dimethyl diazomalonate in the presence of rhodium(II) acetate to give regioselectively 4‐cyano‐2H‐thio‐pyrans 2 (C ₂— S insertion), and 5‐cyano‐2H‐thiopyrans (C ₅— S insertion) were not isolated. Similar insertion was also observed in the reaction of 1 with methyl diazoacetoacetate and ethyl diazobenzoylacetate. The starting compounds 1 were synthesized by the reaction of tetrahydro‐4‐oxo‐3‐thiophene‐carbonitrile with morpholine, piperidine, and pyrrolidine in the presence of formic acid in ethanol.     

N‐Heterocyclic Carbene‐Catalyzed Benzoin Strategy for Divergent Synthesis of Cyclitol Derivatives from Alditols

A divergent synthesis of cyclitol derivatives has been developed utilizing an N‐heterocyclic carbene‐catalyzed benzoin‐type cyclization of C₂‐symmetrical dialdoses. The resulting inososes are versatile intermediates, which are readily converted into not only inositols but also amino‐, deoxy‐, O‐methyl‐ and C‐methyl‐inositols.

     

Facile and regioselective synthesis of thiazolidin-4-one derivatives catalyzed by basic ionic liquid [bmim]OH under ultrasonic irradiation

2-Iminothiazolidin-4-one derivatives were synthesized regioselectively in good to high yields by condensation of N,N-disubstituted thioureas and ethyl chloroacetate in the presence of basic ionic liquid [bmim]OH as a catalyst under conventional and ultrasonic irradiation conditions. Under ultrasonic irradiation, the reaction furnished the desired 2-iminothiazolidinones in higher yields (76–87%) and lower reaction times (30–55 min).