S. V. Makarenko

Organic chemistry. History and mutual relations of universities of Russia

The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now.

3-(Nitromethyl)-3,4-dihydroquinoxalin-2(1H)-ones: synthesis and structure

Reactions of ethyl 3-nitroacrylate with o-phenylenediamine and its substituted derivatives were used for the synthesis of 3-(nitromethyl)-3,4-dihydroquinoxalin-2(1H)-ones, followed by structural characterization. These compounds were found to undergo elimination of nitromethane, leading to quinoxalin-2(1H)-ones.

Synthesis and structure of 2-(nitromethylene)-2H-1,4-benzothiazin-3(4H)-one

A new representative of benzothiazines, (2Z)-2-(nitromethylene)-2H-1,4-benzothiazin-3(4H)-one, was synthesized, and its structure was studied. According to 1H NMR, IR, and UV spectral and X-ray diffraction data, the molecules are planar highly conjugated structures that exist in crystal as centrosymmetric dimers; the latter form layers overlapping with each other and held together by strong π-π interaction between the carbonyl groups of neighboring layers.

Synthesis Approach to Functionalized Chromens

Chromene (benzopyran) ring is a key fragment of some drugs. In particular, it is a part of the molecules of known blood anticoagulants warfarin [1, 2] and neodicoumarinum [3], antitumor drug 8-methoxypsoralen, or furocoumarin [1], and it forms also the structure of tocopherols (vitamin E), the natural antioxidants [1]. Synthetic representative of the benzopyran series, cromakalim, shows antihypertensive properties [1]; some benzopyrans containing electronacceptor substituents at the third position of the ring show radioprotective effect [4]. We synthesized the functionalized chromenes on the basis of reaction of 1-bromo-1-nitro-3,3,3-trichloropropene I with salicylic aldehyde and its derivatives. The reaction proceeds at 18–20°С in chloroform or dichloromethane solution in the presence of equimolar amount of triethylamine (method a) to give a readily separated mixtures of the respective chromanols II–V and chromenes VI–IX in 33 and 40% yields, respectively, and at using a two-fold excess of this base (method b) only the corresponding chromenes VI–IX were obtained. DOI: 10.1134/S1070363211010294

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with O- and N-nucleophiles

Reactions of 1-bromo-1-nitro-3,3,3-trichloropropene with alcohols, benzidine and o-, m-, and p-phenylenediamines was investigated and the reaction conditions were developed. The alkoxylation and amination products and an unusual nitrogen-containing bis-aziridine were obtained; their structures were characterized by the spectral (IR, 1H, 13C NMR, HMQC, and HMBC) methods.

One-Pot Synthesis of Tetrahydrobenzofuran-3-carboxylates

Benzofuran cycle is constituent of some natural compounds and drugs [1–3]. In particular, tetrahydrobenzofuran fragment contributes to the composition of sesquiterpenoids ligularone and isoligularone [4], and benzodihydrofuran system is present in the molecules of such antifungal antibiotics as griseofulvin and sodium usninate [5]. We developed a convenient one-pot approach to tetrahydrobenzofuran series representatives II and III on the basis of condensation of methyl-3-bromo-3nitroacrylate I with cyclic β-diketones: dihydroresorcin and dimedone. Reaction proceeds at reflux of equimolar amounts of reagents in methanol in the presense of potassium acetate. DOI: 10.1134/S1070363210050361

Alkyl 2,3-dibromo-3-nitroacrylates in the reaction with o-phenylenediamine

Alkyl 2,3-dibromo-3-nitroacrylates [1] are new representatives of the class of halonitroethenes [2–7] containing in vicinal position at the double bond carbon atoms two bromine atoms and easily modifiable nitro and alkoxycarbonyl functional groups. The combination of such substituents predetermines a wide synthetic potential of dibromonitroacrylates and adds originality to their properties in comparison with known monoand dihalonitroethenes [2, 8–11], especially in the reactions with binucleophilic reagents.

Alkyl 3-nitroacrylates: Synthesis and reactions with cyclohexane-1,3-diones and Meldrum’s acid

A modified procedure was proposed for the synthesis of alkyl 3-nitroacrylates by nitroiodination of alkyl acrylates and subsequent dehydroiodination of iodonitropropanoates with triethylamine. Alkyl 3-nitroacrylates reacted with cyclohexane-1,3-dione, dimedone, and Meldrum’s acid in the presence of N,N,N-tri-methylanilinium hydroxide (Rodionov’s catalyst) in anhydrous methanol to give the corresponding Michael adducts.

Furan-containing gem-bromonitroethenes: Synthesis and reaction with morpholine

The first time the representative of furan-containing gem-bromonitroethenes 5-nitro-2-(2-bromo-2-nitro-ethenyl)furan was synthesized by bromination of 5-nitro-2-(2-nitroethenyl)furan followed by dehydrohalogenation of the dibromide. Morpholine adducts of the synthesized β-substituted gem-bromonitroethene and its analog with a 5-bromo-2-furyl substituent were obtained. The structures of the gem-bromonitroethenes and aza adducts were characterized by spectral methods (IR, UV, 1H, and 13C-{1H} NMR, including 1H-13C HMQC and HMBC).

2-Pyrrolidones containing pyridine and benzimidazole: Synthesis and structure

Hydrolysis of 4-heteryl-3-methoxycarbonyl-2-pyrrolidones in an alkaline medium and subsequent decarboxylation of the resulting 2-pyrrolidine-3-carboxylic acids afforded 4-(pyrid-3-yl)- and 4-(1-methylbenzimidazol-2-yl)-2-pyrrolidones.