Syntheses of 1-Azaazulan-2-One Analogs of Adrenergic Agents

The Friedel-Crafts reaction of 1-azaazulan-2-ones with α-haloacid chloride in the presence of aluminum trichloride gives the corresponding α-haloacyl derivatives. Treatment of these reaction products first with various secondary amines and then with sodium borohydride gives new adrenergic active amine derivatives.     

Cinnamylation studies of 5,7-dihydroxy-2-methylisoflavone and chromone

Cinnamylation of 5,7-dihydroxy-2-methyl-isoflavone and chromone with cinnamyl alcohol in the presence of aqueous acetic acid yields 6,8-dicinnamyl- and 8-cinnamyl- derivatives, respectively. On the other hand, cinnamylation with cinnamyl bromide in the presence of methanolic sodium methoxide affords the corresponding 6-cinnamyl derivatives along with the same dicinnamyl derivatives. Cyclodehydrogenation of the monocinnamyl derivatives with DDQ is sluggish and gives the corresponding flavenes only in small yields.     

Preparation of 1-dialkylamino-1,2,3-trienes,a novel type of cumulenes

Solutions of α-lithiated cumulenic amines are produced upon treatment of l-dialkylamino-4-methoxy-4-methyl-2-pentynes with two equivalents of butyllithium. Subsequent protonation with t-butyl alcohol gives the corresponding cumulenic amines, while treatment with trimethylchlorosilane gives the α-trimethylsilylated derivatives.     

Conversions of 1-arylamino-3-phenyloxindoles

Acetylation of 1-arylamino-3-phenyloxindoles by acetic anhydride in the presence of an acidic catalyst (TsOH) gives N-acetyl derivatives; alkylation by methyl iodide in the presence of sodium ethoxide gives C₍₃₎- and N-dimethyl derivatives. Reduction by lithium aluminum hydride gives 1-arylamino-3-phenylindolines, which form the corresponding indoles when they are oxidized by chloranil.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1362–1365, October, 1984.     

Asymmetric protonation of lithium enolates of alpha-amino acid derivatives with alpha-amino acid-based chiral Brønsted acids

The reaction of lithium enolates of alpha-amino acid derivatives with chiral amides, easily synthesized from L-tert-leucine, gives corresponding optically active unnatural alpha-amino acid derivatives with up to 87% ee.     

Synthesis of anthradipyridone derivatives

Anthradipyridones containing pyridinium groups in one or two pyridone rings were obtained by the action of pyridine on 6-chloroacetamido derivatives of anthrapyridone and on 1,4- and 1,5-di(chloroacetamido)anthraquinones. Heating of the anthradipyridonyl-pyridinium salts in aniline gives the corresponding mono- and diamino derivatives of anthradipyridones, while reduction gives unsubstituted anthradipyridones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 830–835, June, 1973.     

2-(3-Acetylamino-2,2-dimethylcyclobutyl)-methyl-4(3H)-quinazolinones

Beckmann rearrangement of N-[3-(1-hydroxyimino)ethyl-2,2-dimethylcyclobutyl]acetylanthranilic acid, and its 5-bromo and 4-chloro derivatives gives the corresponding N-(3-acetylamino-2,2-dimethylcyclobutyl)acetylanthranilic acids. Treatment of these acylanthranilic acids with formamide gives 2-(3-acetylamino-2,2-dimethylcyclobutyl)methyl-4(3H)-quinazoline and its 6-bromo and 7-chloro derivatives.     

Reactions of α-chloroethers in presence of zinc

Reaction of α-chloroethers with zinc in the presence of thiophene and furan derivatives gives the corresponding diheterylalkanes.     

Hydro- and silylcyanation of cholic acid derivatives. Synthesis of novel pincer ligands based on litocholic acid

Reactions of 3-oxo derivatives of cholic acid esters with acetone cyanohydrin and trimethylsilyl cyanide lead to exclusive or predominant formation of the corresponding 3-cyano-3-hydroxy and 3-cyano-3-trimethylsiloxy derivatives with axial orientation of the cyano group. Reduction of the cyano group in the addition products gives 3-aminomethyl derivatives which can be used to obtain pincer ligands containing two cholane fragments.     

Heterocyclic silyl enol ether chemistry: Synthesis and reactivity of 3-trimethylsiloxyfuran and 3-trimethylsiloxythiophene

The preparation of the titte compounds is reported starting from the corresponding bromo derivatives.3-Trimethylsiloxyfuran gives rise easily to cycloadditions affording bicyclic tetrahydrofuranonic systems.     

Synthesis of 2,3-diformyl-5-ethylbenzofuran and its derivatives

A mixture of 3-formyl and 3-acetoxymethyl derivatives is formed in the oxidation of 2-carbethoxy-3-methyl-5-ethylbenzofuran with selenium dioxide. Reduction of the products with lithium aluminum hydride gives the corresponding 2,3-dihydroxymethyl derivatives, which are converted to 2,3-diformyl derivatives by successive oxidation by the Fetizon method and with manganese dioxide. The corresponding benzofuro[2, 3-d]pyridazines were synthesized by reaction of 2-carbethoxy-3-formyl-5-ethylbenzofuran with hydrazine hydrate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 893–895, July, 1982.     

Pummerer reaction of biotin sulfoxides : an access to new functionalized biotin derivatives.

Application of the Pummerer reaction to Biotin sulfoxides gives a good access to the corresponding thiolactol and thiolactone, which are key-compounds for the synthesis of new functionalized Biotin derivatives.     

Polyazole systems based on 3,4-dihydroisoquinoline

The reaction of 1-methylthio-3,3-dimethyl-6,7-di-R-dihydroisoquinolines with carboxylic acid hydrazides gives the corresponding hydrazides converted into derivatives of 1,2,4-triazolo[3,4-alisoquinoline. Reaction of these dihydroisoquinolines with hydrazine hydrate gives the corresponding 1-hydrazinoderivatives which with NaNO₂ give tetrazolo[5,1-aisoquinolines, and with oxalyl chloride (where R = H), 1,2,4-triazino[5,1-aJisoquinoline.     

Acylation of aromatic ethers over solid acid catalysts: scope of the reaction with more complex acylating agents

Acylation of anisole with 2-phenylbutanoic acid derivatives, over zeolite catalysts, gives the corresponding 4-acyl derivatives with high regioselectivity. In an analogous way, 2,3-dihydrobenzofuran reacts with acid anhydrides or chlorides in the presence of catalytic quantities of zeolites to give the corresponding 5-acyl-2,3-dihydrobenzofurans. The zeolite can be recovered, regenerated and used again to give almost the same yield as with fresh zeolite. The reaction has been applied to the synthesis of ethyl (2,3-dihydrobenzofuran-5-yl)glyoxylate.     

Synthesis of derivatives of 2-amino-3-ethoxycarbonylthiophene

A number of alkylidene esters are synthesized from the corresponding ketones and cyanoacetic ester, and treatment of the esters with sulfur in the presence of a catalytic amount of diethylamine gives 2-amino-3-ethoxycarbonylthiophene derivatives.     

Photoreaction of α-phenylcrotononitrile derivatives: the facile cyclopropane ring formation

Irradiation of 4-methyl, 4,4-dimethyl, and 4,4,4-trimethyl derivatives of 2-phenylcrotononitrile gives the corresponding 1-cyano-1-phenylcyclopropanes in high yields.     

Synthesis of esters of oxathiinecarboxylic and dithiinecarboxylic acids and their derivatives

Conclusions The reaction of the methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid with mercaptoethanol and 1,2-dithioglycol gives derivatives of oxathiine and dithiine. The oxidation of these products gives the corresponding sulfones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1670–1672, July, 1988.     

Synthesis of derivatives of 2-amino-3-ethoxycarbonylthiophene

A number of alkylidene esters are synthesized from the corresponding ketones and cyanoacetic ester, and treatment of the esters with sulfur in the presence of a catalytic amount of diethylamine gives 2-amino-3-ethoxycarbonylthiophene derivatives.     

The use of β-ketothioesters for the exceptionally mild preparation of β-ketoamides

Transamination of t-butylacetothioacetate derivatives with primary and secondary amines in the presence of silver (I) trifluoroacetate gives high yields of the correspondingβ-ketoamides.     

Stereoselective acid-catalyzed homoallylic rearrangement of cyclopropylsilylmethanols: an efficient route to Z-homoallyl derivatives

Treatment of cyclopropylsilylmethanols derived from cyclopropyl silyl ketones with acid catalyst gives the corresponding silyl-substituted homoallyl derivatives in high yields with good stereoselectivity, independent of the substituents on the cyclopropyl ring. Cyclopropylsilylmethanols having a n-, s-butyl or phenyl group on the carbinyl carbon react to afford the E-homoallyl derivatives selectively. On the other hand, the reaction of cyclopropylsilylmethanols having a tert-butyl group gives Z-isomers exclusively. The following protiodesilylation of the resulting homoallyl derivatives proceeds with retention of configuration.