Aminoacetaldehyde Diethyl Acetal Research Articles

Synthesis and Structural Characterization of 1-Arylimidazole-2-thiones and N,N'-Aryldiethoxyethylthioureas with Electronically Diverse Substituents: A Manifold of Hydrogen Bonding Networks.

The 1-arylimidazole-2-thiones, (HmimAr) [Ar = 3,4,5-C6H2(OMe)3, 2,4-C6H3(NO2)(OMe), 2,4,6-C6H2Cl3 and 3,5-C6H3(CF3)2], which feature electronically diverse substituents, may be obtained via acid-catalyzed ring closure of the corresponding N,N'-aryldiethoxyethylthiourea derivatives, ArN(H)C(S)N(H)CH2CH(OEt)2, (H2detuAr), which in turn are obtained via treatment of aminoacetaldehyde diethyl acetal, H2NCH2CH(OEt)2, with the respective arylisothiocyanates (ArNCS). The molecular structures of all of the above N,N'-aryldiethoxyethylthioureas and 1-arylimidazole-2-thiones have been determined by X-ray diffraction, thereby demonstrating that the substituents have a profound effect on the crystal structures. For example, each of the N,N'-aryldiethoxyethylthiourea derivatives adopts a different hydrogen bonding pattern. Specifically, the hydrogen-bonding network in (i) H2detuArCl3 consists of chains of 9-membered rings, with an [ [Formula: see text](9)] motif, that feature one N-H ⋯ O and one N-H ⋯ S interaction, (ii) H2detuArOMe,NO2 consists of chains of 6-membered rings, with an [ [Formula: see text](6)] motif, that feature two head-to-tail N-H ⋯ S interactions, (iii) H2detuAr(CF3)2 consists of a dimer that features two pairs of N-H ⋯ O interactions, of which each pair is a component of an 8-membered ring with an [ [Formula: see text](8)] motif, and (iv) H2detuAr(OMe)3 consists of a chain of head-to-head dimeric rings with a basic [ [Formula: see text](16)] motif, a notable feature of which is that sulfur does not play a role as a hydrogen bond acceptor. Each of the 1-arylimidazole-2-thiones exists as a "head-to-head" hydrogen-bonded dimer in the solid state, with an [ [Formula: see text](8)] motif. However, while the hydrogen-bonded motifs for HmimArCl3 and HmimAr(OMe)3 are planar, those for HmimAr(CF3)2 and HmimArOMe,NO2 are extremely puckered, with fold angles of 24.2° (mean value) and 45.7°, respectively.

ChemInform Abstract: A One‐Pot Coupling—Addition—Cyclocondensation Sequence (CACS) to 2‐Substituted 3‐Acylpyrroles Initiated by a Copper‐Free Alkynylation.

AbstractA novel modular three‐component synthesis of title compounds (IV) and (VII) via sequential reaction of an acid chloride, an alkyne, and aminoacetaldehyde diethylacetal is reported.

Fluorescent properties of novel dendrimer dyes based on thiazole orange

In this paper, polyamidoamine (PAMAM) dendrimers with active amino group of some generations ( G=0.5–2) were prepared from commercial aminoacetaldehyde diethyl acetal by the divergent method. After that, thiazole orange (TO) with –COOH was incorporated with dendrimers of G=1 and 2 to afford novel dendrimer-TO dyes. The fluorescent properties studies showed that the fluorescent intensity of the same concentration of dendrimer-TO ( G=2) was higher than that of the dendrimer-TO ( G=1), and both of them were much stronger than free TO with –COOH. There was a fluorescent enhancement of the dendrimer dyes compared with free dye. The dendrimer dyes were of well-defined chemical structure,with little aggregation and self-quenching as well as good fluorescence properties of good stability, high intensity and sensitivity, which could be used in labeling cancer cells and further in diagnosis and detection of early-stage tumors.

ChemInform Abstract: Alternate and Improved Synthesis of the Cactus Alkaloid Arizonine.

Abstract An alternate and high-yield synthesis of the simple tetrahydroisoquinoline alkaloid arizonine, via the sodium cyanoborohydride mediated reductive amination of 2-benzylpxy-3-methoxyacetophenone with aminoacetaldehyde diethyl acetal, as the key step, is reported.

Reaction of α-aminoacetals with 2-methylresorcinol

The main method of synthesis of calix[4-resorcinols is the condensation of resorcinol and its derivatives with aliphatic or aromatic aldehydes [1–3]. We have recently extended synthetic opportunities of this method by involvement into the reaction with resorcinol of phosphorylated acetals to obtain calix[4] resorcinols with phosphorylalkyl substituents at the lower rim of the molecule [4]. A special attention should be paid to their aminoalkyl analogs that can serve as primary compounds (due to involvement of amino groups) in the syntheses of new cavitands, container compounds, and nanotubes. For the synthesis of the calixarenes of this type we studied reaction of aminoacetaldehyde diethylacetal (Ia) and dimethylaminoacetaldehyde diethylacetal (Ib) with 2-methylresorcinol. We found that synthetic result of this reaction depends considerably on the reaction conditions. The process carried out in dioxane in the presence of trifluoromethanesulfonic acid leads to formation of calix[4]resorcinols IIIa and IIIb as the final products. DOI: 10.1134/S1070363209090199

Concise Stereocontrolled Formal Synthesis of (±)-Quinine and Total Synthesis of (±)-7- Hydroxyquinine via Merged Morita−Baylis−Hillman−Tsuji−Trost Cyclization

Concise stereoselective syntheses of (+/-)-quinine and (+/-)-7-hydroxyquinine are achieved using a catalytic enone cycloallylation that combines the nucleophilic features of the Morita-Baylis-Hillman reaction and the electrophilic features of the Tsuji-Trost reaction. Cyclization of enone-allyl carbonate 11 delivers the product of cycloallylation 13 in 68% yield. Diastereoselective conjugate reduction of the enone 13 (>20:1 dr) followed by exchange of the N-protecting group provides the saturated N-Boc-protected methyl ketone 19, which upon aldol dehydration provides quinoline containing enone 15, possessing all carbon atoms of quinine. Exposure of ketone 15 to L-selectride enables diastereoselective carbonyl reduction (>20:1 dr) to furnish the allylic alcohol 16. Stereoselective hydroxyl-directed epoxidation using an oxovanadium catalyst modified by N-hydroxy-N-Me-pivalamide delivers epoxide 17 (17:1 dr). Cyclization of the resulting amine-epoxide 17 provides (+/-)-7-hydroxyquinine in 13 steps and 11% overall yield from aminoacetaldehyde diethyl acetal. Notably, highly stereoselective formation of five contiguous stereocenters is achieved through a series of 1,2-asymmetric induction events. Deoxygenation of the N-Cbz-protected allylic acetate 22 provides olefin 23, which previously has been converted to quinine. Thus, (+/-)-quinine is accessible in 16 steps and 4% overall yield from commercial aminoacetaldehyde diethyl acetal.

Chemical modification of chitosan 8: preparation of chitosan–dendrimer hybrids via short spacer

Polyamidoamine (PAMAM) dendrimers of various generations ( G=0.5–5) were prepared from commercial aminoacetaldehyde diethyl acetal. After transforming acetal to aldehyde, chitosan–dendrimer hybrids were prepared by reductive N-alkylation. The reactivity of dendrimer to primary amino group of chitosan was decreased at G=3.5 or above MW>6305. Chitosan–sialodendrimer hybrid ( G=3) was also prepared under the same conditions.

A derivative of diethylenetriaminepentaacetic acid for europium labeling of proteins.

Preparation of a reagent that will incorporate diethylenetriaminepentaacetic acid (DTPA) into proteins under mild conditions and make a strong europium chelate is described. Aminoacetaldehyde diethyl acetal was reacted with DTPA dianhydride, and mono- and disubstituted products as well as unsubstituted DTPA were separated by gel filtration. The monosubstituted product, after conversion into the corresponding aldehyde by mild acid hydrolysis, is conjugated to protein or other amino-containing compounds via reductive amination at neutral pH. Although the DTPA-Eu-labeled proteins are themselves not fluorescent, a strong fluorescence of europium can be generated easily by the dissociation-enhancement mechanism. A direct measurement of lectin-ligand interaction using Eu-labeled ligand and lectin immobilized on 96-well plate illustrates that the assay utilizing Eu fluorescence is as sensitive as the radioactive assays.

Alternate and Improved Synthesis of the Cactus Alkaloid Arizonine

Abstract An alternate and high-yield synthesis of the simple tetrahydroisoquinoline alkaloid arizonine, via the sodium cyanoborohydride mediated reductive amination of 2-benzylpxy-3-methoxyacetophenone with aminoacetaldehyde diethyl acetal, as the key step, is reported.

ChemInform Abstract: Synthesis of Key Carbazoles. Intermediates for Polymethoxyellipticines and Olivacines.

AbstractFormylation of the carbazole (I) with N‐methylformanilide (II) yields the aldehyde (III) which is coupled with aminoacetaldehyde diethyl acetal (IV) to produce the corresponding unstable Schiff base.

Synthesis of Isoquinoine Precursors by Photoamination of Stilbenes with Bifunctional Alkylamines

Irradiation of stilbenes with amino alcohols or amino acetaldehyde diethyl acetal in the presence of p-dicyanobenzene gave the corresponding N-substituted 1,2-diarylethylamines in good yields. The resulting benzylamino alcohols and benzylamino acetals were treated with CH 3 SO 3 H and gaseous BF 3 , respectively, to give isoquinolines.

ChemInform Abstract: Reaction of Dimethyl N‐Aryl‐ and N‐Alkylcarbonimidodithioates with Aminoacetaldehyde Diethyl Acetal: A Direct Synthesis of 1‐Aryl‐ and 1‐Alkyl‐2‐methylthioimidazoles.

ChemInformVolume 19, Issue 19 Heterocyclic Compounds ChemInform Abstract: Reaction of Dimethyl N-Aryl- and N-Alkylcarbonimidodithioates with Aminoacetaldehyde Diethyl Acetal: A Direct Synthesis of 1-Aryl- and 1-Alkyl-2-methylthioimidazoles. D. POORANCHAND, D. POORANCHAND Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this authorH. ILA, H. ILA Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this authorH. JUNJAPPA, H. JUNJAPPA Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this author D. POORANCHAND, D. POORANCHAND Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this authorH. ILA, H. ILA Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this authorH. JUNJAPPA, H. JUNJAPPA Dep. Chem., North-Eastern Hill Univ., Shilling-793003, Meghalaya, IndiaSearch for more papers by this author First published: May 10, 1988 https://doi.org/10.1002/chin.198819173Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue19May 10, 1988 RelatedInformation

Reaction of DimethylN-Aryl- andN-Alkylcarbonimidodithioates with Aminoacetaldehyde Diethyl Acetal: A Direct Synthesis of 1-Aryl- and 1-Alkyl-2-methylthioimidazoles

The reaction of dimethyl N-aryl- or N-alkylcarbonimidodithioates with aminoacetaldehyde diethyl acetal in refluxing acetic acid affords 1-aryl or 1-alkyl-2-methylthioimidazoles in good yields. Dimethyl N-isopropylcarbonimidodithioate gave 1-isopropylimidazole-2(3H)-thione under similar conditions.

Synthesis of dl-4-hydroxycrebanine.

4-Hydroxycrebanine (2), a natural product from Stephania sasakii HAYATA, was synthesized via 1-(6'-bromo-2', 3'-dimethoxybenzyl)-4-hydroxy-2-methyl-6, 7-methylenedioxy-1, 2, 3, 4-tetrahydroisoquinoline (17), which was obtained by Bobbitt's modification of the Pomeranz-Fritsch cyclization of N-[2-(6'-bromo-2', 3'-dimethoxyphenyl)-1-(3, 4-methylenedioxy phenyl) ethyl] aminoacetaldehyde diethyl acetal (12). Irradiation of the compound (17) with the cis relationship of C1-H and C4-H gave dl-4-hydroxycrebanine (2) and its isomer (2a). The stereostructures of the two isomers were established firmly by direct comparison of the proton nuclear magnetic resonance spectra.

N-Nitroso-2-hydroxymorpholine, a mutagenic metabolite of N-nitrosodiethanolamine.

N-Nitroso-2-hydroxymorpholine was synthesized from N-(2-hydroxyethyl)aminoacetaldehyde diethylacetal by nitrosation and hydrolysis. It was detected as a metabolite of N-nitrosodiethanolamine in rat hepatic 9000 g supernatant. It was mutagenic toward Salmonella typhimurium TA 1535, with and without activation. The results suggest that N-nitroso-2-hydroxymorpholine, which is formed by metabolic beta-oxidation of N-nitrosodiethanolamine, could be involved in carcinogenesis by N-nitrosodiethanolamine.

Preparation of anomeric pairs of 1-thioglycosides: use of anomerization catalyzed by boron trifluoride

Anomeric pairs of some alkyl 1-thioaldopyranosides of d-galactose, d-glucose, d-mannose, 2-acetamido-2-deoxy- d-glucose, 2-acetamido-2-deoxy- d-galactose, and l-fucose were prepared. The per- O-acetylated, 1,2- trans anomers of 6-(trifluoroacetamido)hexyl 1-thioaldopyranosides and 5-(methoxycarbonyl)pentyl 1-thioaldopyranosides were anomerized with boron trifluoride in dichloromethane. The anomeric mixtures were then separated by chromatography, using columns of either silica gel or an ion-exchange resin. De-blocking of the separated compounds provided pure anomers of 6-aminobexyl 1-thioaldopyranosides or 5-carboxypentyl 1-thioaldopyranosides. The aglycons of the latter glycosides were further extended by reaction with aminoacetaldehyde diethyl acetal, which, after deacetalization of the products, provided an ω-aldehydo group. These series of glycosides could be readily coupled to proteins or solid matrices.

A new approach to the synthesis of ellipticines

1,4-Dimethylcarbazole-3-carbaldehyde (2a) was condensed with aminoacetaldehyde diethyl acetal, and the Schiff's base was hydrogenated before conversion into the N-tosyl derivative (3a). The latter was cyclised in boiling dilute hydrochloric acid in dioxan to ellipticine [5,11-dimethyl-6H-pyrido[4,3-b]carbazole)(1a)(87%). N-Tosyl-3,4-dihydroellipticine (4) was shown to be an intermediate. Under the same conditions, m-methoxyanilinoacetaldehyde diethyl acetal (6a) gave a low yield (5%) of 6-methoxyindole, but its N-methyl derivative (6b) gave 4- and 6-methoxy-N-methylindoles in 11 and 32% yields, respectively.Condensation of 6- methoxy-1-methylindole with hexane-2,5-dione in ethanol containing toluene-p-sulphonic acid gave 7-methoxy-1,4,9-trimethylcarbazole (9a)(58%) and 1,2,3,4-tetrahydro-7-methoxy-1,4-bis-(6-methoxy-1-methylindol-3-yl)-1,4,9-trimethylcarbazole (10), which on heating with toluene-p-sulphonic acid in boiling chloroform gave the carbazole (9a). Treatment of the latter (9a) with pyridinium bromide perbromide gave 6-bromo-7-methoxy-1,4,9-trimethylcarbazole (9b). Formylation of (9b) with N-methylformanilide and phosphoryl chloride gave a complex mixture of N-methylcarbazoles resulting in part from ipso-attack of the Vilsmeier etectrophile at C-6.2,5-Dimethyl-4-acetamidobenzaldehyde (13) was condensed with aminoacetaldehyde diethyl acetal, and the-Schiff's base (14) formed was hydrogenated to 4′-(2,2-diethoxyethylaminomethyl)-2′,5′-dimethylacetanilide (15a). The N-tosyl derivative (15b) on boiling with dilute hydrochloric acid in dioxan gave only the corresponding aldehyde (16), but coupling of (15b) with p-bromoanisole under Goldberg conditions gave 4′-[N-(2,2-diethoxyethyl)tosylaminomethyl]-N-(4-methoxyphenyl)-2′,5′-dimethylacetanilide (17a)(75%). Similarly, (15b) coupled with m-bromoanisole gave 4′-[N-(2,2-diethoxyethyl)tosylaminomethyl]-N-(3-methoxyphenyl)-2′,5′-dimethylacetanilide (17b)(66%). Goldberg coupling of p-bromoanisole and 2,5-dimethylacetanilide gave N-(4-methoxyphenyl)-2′,5′-dimethylacetanilide (18a), which on irradiation afforded 4-acetyl-N-(4-methoxyphenyl)-2,5-dimethylaniline (18b), 2-acetyl-N-(2,5-dimethylphenyl)-4-methoxyaniline (18c), and 6-methoxy-1,4-dimethylcarbazole (2b).

Ellipticine analogs: Oxygen and sulfur isosteres

AbstractOxaellipticine has been synthesized from 1,4‐dimethyldibenzofuran, by converting it to the 2‐aldehyde, forming the Schiff's base with aminoacetaldehyde diethyl acetal, and cyclizing this with 105%superphosphoric acid. Alternatively, tetrahydrodimethyldibenzofuran was formylated mainly at the 3‐position, and the 3‐(2‐nitrovinyl) derivative of the 3‐aldehyde, by hydride reduction, then Bischler‐Napieralski cyclization of the 3‐(2‐formamidoethyl) derivative, afforded hexahydrooxaellipticine, which could be aromatized only in poor yield. Isooxaellipticine, the pyrido‐A' positional isomer, was similarly prepared from the nitrovinyl derivative of 1,4‐dimethyl‐2‐dibenzofurancarboxaldehyde, through cyclization of the formamidoethyl intermediate and aromatization of the dihydro product. Likewise, isothiaellipticine was obtained from 1,4‐dimethyl‐2‐dibenzothiophenecarboxaldehyde.