Phosphorus acid derivatives from 3,6-di-tert-butylpyrocatechol

Conclusions The reaction of 3,6-di-tert-butylpyrocatechol with the acid chlorides of various phosphorus acids was studied: reaction with PCl₃ gives the spirophosphorane, while reaction with diphenylchlorophosphine gives the diphenyl-1,2-phenylenedioxyphosphorane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2385–2388, October, 1978.     

Novel synthesis of cis-3,5-disubstituted morpholine derivatives

1-tert-Butyl-2-(allyloxymethyl)aziridine has been transformed for the first time diastereoselectively into cis-3,5-di(bromomethyl)-4-tert-butylmorpholine via an electrophile-induced ring closure using bromine in dichloromethane. The latter morpholine has been used as a substrate for the synthesis of the corresponding 3,5-di(methoxymethyl)morpholine and 3,5-di(cyanomethyl)morpholine upon nucleophilic displacement of both bromo atoms. Further evaluation of this protocol toward the synthesis of 4-arylmethyl- and 4-alkylmethyl-3,5-di(bromomethyl)morpholines showed that the premised cyclization of the corresponding 2-(allyloxymethyl)aziridines into 3,5-di(bromomethyl)morpholines only proceeded well for the N-neopentylmorpholine, which was subsequently transformed into a 3-oxa-7-thia-9-azabicyclo[3.3.1]nonane derivative. Also, in some other cases, the desired 3,5-di(bromomethyl)morpholines were isolated in low yields and transformed into the corresponding 3,5-di(cyanomethyl)morpholines.     

N-salicylideneamine derivatives with TEMPO substituents

Three N-salicylideneamine derivatives bearing TEMPO (2,2,6,6-tetra- methyl-1-piperidinyloxy) substituents were prepared in order to study their structure and property relationships and to investigate the possibilities of the existence of heat and/or light responsive magnetic properties. Curie-Weiss behavior with weak ferromagnetic intermolecular spin-spin interactions was observed in one of the radicals, while antiferromagnetic interactions were predominant for the other radicals and the structure-property relationships were investigated for the radical compounds from their crystal structures obtained by X-ray analyses. Preliminary results of the examination of their responses towards light and heat are also described.     

Novel phthalocyanines with naphthalenic substituents

Phthalocyanines with four naphthyl-malonic ester groups on the periphery were synthesized by cyclotetramerization of 4-(1,1-dicarbethoxy-2-(1-naphthyl)-ethyl)-phthalonitrile. The new compounds were characterized by spectroscopic methods. The electronic spectra exhibit intense π–π* transitions from the naphthyl moiety together with the characteristic Q and B bands of the phthalocyanine core. The electrochemical properties of the 2,9,17,23-tetra-(1,1-(dicarbethoxy)-2-(1-naphthyl)-ethyl) phthalocyaninato copper(II) complex were studied by cyclic voltammetry.     

Mesogenic benzothiazole derivatives with methoxy substituents

Two new mesogenic homologous series containing 6-methoxybenzothiazole ring at the terminus of the molecule, viz. 2-(4′-n-alkoxyphenylazo)-6-methoxybenzothiazoles and 2-[4′-(4″-n-alkoxy-benzoyloxy) phenylazo]-6-methoxybenzothiazoles were synthesized. In series I,n-butyloxy to n-tetradecyloxy derivatives exhibit nematic mesophase. Smectic A mesophase commences from then-dodecyl-oxy derivative as a monotropic phase and is retained up to the last member synthesized. All the members of series II exhibit enantiotropic nematic mesophase. The mesomorphic properties of the present series are compared with other structurally related series to evaluate the effect of the benzothiazole ring and the methoxy substituent on mesomorphism. This paper was presented at the 10th National Conference on Liquid Crystals held at Bangalore during 9–11 October 2003     

Influence of substituents in salicylaldehyde molecule on interaction with 2-imino-3,5-dimethylthiazolidine

Salicylaldehyde, 5-chlorosalicylaldehyde, or o-vanillin will react with 2-imino-3,5-dimethylthiazolidine to form previously unknown bis(3,5-dimethylthiazolidin-2-ylideneamino)-2-hydroxyphenylmethanes. If strong electron-acceptor groups are present on the aromatic ring, an acid-base interaction takes place. Thus, 3-nitro-5-methoxy-, 3-nitro-5-chloro-, and 3-bromo-5-nitrosalicylaldehyde react with the heterocyclic base to form saltlike complexes, the structure of which has been confirmed by x-ray diffraction.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 420–425, March, 1993.     

Preparation of 2-deoxystreptamine derivatives with all-axial substituents for desymmetrization

2-Deoxystreptamine derivatives with all-axial substituents were prepared with new methods. They are potential compounds for desymmetrization.     

Studies on 3,5-diaminopyrazole derivatives

The behaviour of 3,5-diamino-4-phenylazopyrazole toward a variety of reagents is reported. Several new 3,5-diaminopyrazole derivatives as well as amino derivatives of fused pyrazoles have been prepared.

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Untersuchungen an 3,5-Diaminopyrazol-Derivaten

Zusammenfassung Es wird über das Verhalten von 3,5-Diamino-4-phenylazopyrazol gegenüber verschiedenen Agentien berichtet. Es wurden sowohl einige neue 3,5-Diaminooyrazol-Derivate als auch einige Aminoderivate von kondensierten Pyrazolen dargestellt.

     

Synthesis and mesomorphic properties of benzoxazole derivatives with lateral multifluoro substituents

Fluorinated aromatics is generally chosen as mesogenic cores to design novel liquid crystal compounds. Here, a series of benzoxazole derivatives with laterally multifluorinated biphenyl units, 2-(3′,3-difluoro ?4′-alkoxy-1,1′-biphenyl-4-yl)-benzoxazole derivatives (coded as nPF(3)PF(3)Bx), are synthesized and characterized, where methyl and nitro moieties are selected as terminal groups to investigate the effects of different polar substituents on the liquid crystal properties. The compounds nPF(3)PF(3)Bx show enantiotropic mesophases with mesophase ranges of 0–40°C and 0–63°C on heating and cooling for hydrogen-terminated derivatives (nPF(3)PF(3)BH), 43–93°C and 54–123°C for methyl-terminated ones (nPF(3)PF(3)BM), 60–108°C and 74–152°C for nitro terminated ones (nPF(3)PF(3)BN), respectively. They exhibit photoluminescence emission peaks at 390–392 nm and UV–vis absorption bands with maxima at 327–330 nm, respectively. The results reveal that lateral multifluoro substituents lead to a decrease in melting/clearing points, while electron-withdrawing terminal nitro moiety results in increases in both melting point and mesophase range.     

Novel radical compounds bearing mesogenic cores with long alkyl substituents

Series of aminoxyl radicals (TEMPO or nitronyl nitroxide radicals) bearing phenyl benzoate, troponoid, or biphenylcarbonitrile as mesogenic cores with long alkyl substituents were prepared. Although most aminoxyl radicals showed only weak antiferromagnetic interactions due probably to the remote spin centers as clarified by the X-ray analysis of 4a and no appreciable mesogenic phase was observed in each compound, an unusual magnetic transition from an original Curie-Weiss phase to another magnetic phase well-expressed by a singlet-triplet (ST) model was disclosed through the thermal transition in the 4'-undecyloxy-4-biphenylcarbonitrile derivative with oxocarbonyl-TEMPO 12b.     

Synthesis of 3,5-disubstituted pyrazole derivatives with a carbamate function

One-pot reaction of 1,3-dipolar cycloaddition of aryldiazamethanes generated in situ from the sodium salts of tosylhydrazones of benzaldehyde, p-nitro-, p-methoxy-, and 3,4-dimethoxybenzaldehyde to propargyl-N-phenyl carbamate under heating led to the formation of 3,5-disubstituted pyrazoles in good yield and high regioselectivity.     

Quinaldine derivatives with fluorine-containing substituents and cyanine dyes based on them

Condensation of fluorine-containing anilines with paraldehyde gave quinaldine derivatives with CF₃, CF₃S, and CF₃SO₂ groups in the 6 position, from which carbocyanine, merocyanine, and styryl dyes were synthesized. Fluorine-containing groups lower the basicity of quinaldine by 0.7–2.0 pK_a units and lead to deepening of the color of the dyes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 76–78, January, 1978.     

Preparation and investigation of solutions of chitosan derivatives with long-chain hydrophilic substituents

The preparation of aqueous solutions of chitosan oligo(ethylene oxide) sulfonate and special features of their viscosity and foam-stabilizing properties are described. It is shown that the complete dissolution of the chitosan derivative takes place at a degree of substitution of at least 0.75. An increase in the degree of substitution to 1 leads to a decrease in the viscosity of solutions; however, the viscosity of solutions of chitosan oligo(ethylene oxide) sulfonate in all cases greatly exceeds that of solutions of chitosan acetate of the same concentration. Unlike chitosan acetate solutions, the solutions of chitosan oligo(ethylene oxide) sulfonate have a higher stability and more pronounced foam-stabilizing properties.     

Radiation-induced polymerization of styrene derivatives having alkylamino substituents

The polymerizability of styrene derivatives having alkylamino substituents, such as 1-(2-isopropylaminoethyl)-4-vinylbenzene (IPVB), 1-(2-diethylaminoethyl)-4-vinylbenzene (DEVB) and 1-(2-dimethylaminoethyl)-4-vinylbenzene (DMVB), was investigated in the range −96 to +25° with gamma-rays from a ⁶⁰Co source. The glass transition temperatures were found to be −94° for IPVB, −102° for DEVB and −114° for DMVB. The polymer yield of these monomers prepared by 4 × 10⁶ rad irradiation at −55° was 39.9, 10.4 and 4.9% respectively. On the other hand, the polymer yield of IPVB as a function of irradiation temperature (irradiation dose: 4 × 10⁶ rad) was 2.4% at −96°, 27.4% at −78°, 39.9% at −55°, 35.7% at −37°, 36.4% at −24°, 54.8% at 0° and 71.3% at +25°. Such a trend of temperature-dependent polymer yield also decreased markedly in the order IPVB, DEVB and DMVB. The polymers prepared were soft and gummy, although polymers prepared by irradiating at the doses of 1 × 10⁷ or above were hard and transparent.