Studies on Silicon-Containing Fragrance Raw Materials( Ⅱ )——Syntheses and Odors of 4-Trimethylsilylcyclohex-3-enol and 4-Trimethylsilylcyclohexanol Derivatives

1-Substituted- 4-trimethylsilylcyclohex- 3-enol and 1-substituted- 4-trimetnylsilyl-cyclohexanol, 4-trimethylsilylcyclohex-3-enol and 4-trimethylsilylcyclohexanol, and some of their esters and carbon counterparts were synthesized. Structures of the nineteen new compounds were determined by 1H NMR, IR and MS. Their odors are evaluated.     

含硅香原料研究(VI)－顺(反)-1-取代-3-三甲硅基环己醇的合成、13C NMR谱及其香气评定

合成并分离得到７对１－取代－３－三甲硅基环己醇的顺、反异构体,它们的结构通过＾Ｈ ＮＭＲ、＾１３Ｃ ＮＭＲ、ＭＳ谱及ＧＣ（测其纯度）测定,利用＾１３Ｃ ＮＭＲ确定了各对顺、反异构体的构型。评定了各化合物的香气,大部化合的具有甜香或甜香与木香香气,其中（反）－１－正丁基－３－三甲硅基环己醇具有甜香和木香香气,香气透发,留香持久,质量上乘。     

Studies on Fragrance Raw Materials of α-Terpineol Analogues

Thirty four α-substituted or α, α-disubstituted-( 1-methylcyclohexen-4-yl )methanols and α-substituted or α,α-disubstituted-(4-methylcyclohexyl) methanols weresynthesized. Thirty two of them are new compounds. 1H NMR and IR spectra of allthe compounds were determined, MS spectra of some of them were obtained as well.The characteristic odors were evaluated.Keywords Fragrance raw materials,α-Terpineol analogues, Synthesis, Structuredetermination     

Synthesis and some properties of cyclic acetals of malonaldehyde

The Lewis acid-catalyzed addition of cyclic orthoformates to vinyl ethyl ether, which leads to the formation of malonaldehyde acetals, was studied. It is shown that of the linear-cyclic malonaldehyde acetals, 2-(2,2-diethoxyethyl)- and 5,5-dimethyl-2-(2,2-diethoxyethyl)-1,3-dioxanes are stable. The transacetalization of 1,1,3,3-tetraethoxypropane with 1,2- and 1,3-diols, which leads to the formation of cyclic malonaldehyde acetals, was studied. The physicochemical constants of the acetals were determined, and their ¹H and ¹³C NMR spectra are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 459–463, April, 1983.     

Synthesis and Structure of New <Emphasis Type="Italic">gem</Emphasis>-Diols with 1,2,3-Triazole Fragment

α-(1,2,3-Triazole)-substituted acetals were obtained using the click procedure. Under acid hydrolysis conditions these acetals were converted into earlier unknown stable gem-diols containing a triazole ring.     

含硅香原料研究(Ⅵ)——顺(反)-1-取代-3-三甲硅基环己醇的合成、13CNMR谱及其香气评定

合成并分离得到7对1-取代-3-三甲硅基环己醇的顺、反异构体,它们的结构通过¹HNMR、¹³CNMR、MS谱及GC(测其纯度)测定,利用¹³CNMR确定了各对顺、反异构体的构型.评定了各化合物的香气,大部分化合物具有甜香或甜香与木香香气,其中(反)-1-正丁基-3-三甲硅基环己醇具有甜香和木香香气,香气透发,留香持久,质量上乘.     

4-Hydroxycoumarin/2-hydroxychromone tautomerism: Infrared spectra of 3-substituted-2-13c-4-hydroxycoumarins

By isotopic replacement of the carbonyl carbon with ¹³C, the C?O stretching frequency was identified as the highest frequency strongly absorbing band in the 1550–1750 cm^?1 region of the infrared spectra of several 3-substituted 4-hydroxycoumarins and 3-substituted 4-alkoxycoumarins. The compounds selected for study were either known to crystallize as the coumarin tautomeric form by x-ray diffraction studies or were congeners of such compounds. The carbonyl band varied from 1664 cm^?1 in inter- or intramolecularly hydrogen bonded derivatives to 1718 cm^?1.     

Synthesis of cyclic acetals of acetylenic carbonyl compounds

A condensation of α-acetylenic carbonyl compounds and their acyclic acetals with 1,2-diols gave substituted 1,3-dioxacycloalkanes in up to 90% yields. 2,4-Disubstituted 1,3-dioxolanes were formed as mixtures of steric isomers, in which trans-forms predominated according to the B3LYP/6-311+G(2d,p) calculations.     

Nitrogen bridgehead compounds,part 68. Studies on quinolizine derivatives. Part 2. Synthesis of 1,3-disubstituted-4H-quinolizine derivatives

Quinolizine compounds 1 and 2 or their monocyclic tautomers 3 and 4 have been synthesized using 2-pyri-dineacetic acid derivatives 6a, b, A, B and ethoxymethylenemalonic acid derivatives 7a, b, c in base catalyzed or thermic reaction. In the 6-unsubstituted series, both the 4-oxo and 4-imino derivatives could have been obtained, in the 6-substituted series, however the 4-oxo ones only, whereas instead of the 4-imino derivatives, their monocyclic tautomers 3, 4 have been isolated. In the 6-unsubstituted series, the primarily formed 4-imino compounds have been rearranged into 4-oxo ones under stronger conditions. The structure of the isolated compounds have been proved by ultraviolet, infrared and ¹H nmr spectra, that of 3B=C by X-ray analysis as well.     

Chelation-Controlled Regioselection in Palladium-Catalyzed Carbonyl Allylation by 4-Pentene-1,3-Diol or Its Cyclic Carbonate

With cat. PdCl₂(PhCN)₂ and SnCl₂, 4-pentene-1,3-diol caused regioselective carbonyl allylation at 3-position in DMF to produce 2-substituted 3-vinyltetrahydrofurans and/or 1-substituted 2-vinylbutane-1,4-diols, and cyclic carbonate of 4-pentene-1,3-diol caused regioselective carbonyl allylation at terminal 5-position in THF to produce 1-substituted 3-hexene-1,6-diols.     

Synthesis and Antimicrobial Activities of Novel Series of 1-((4-Methyl-2-Substituted Thiazol-5-yl)Methyleneam INO)-2-Substituted Isothiourea Derivatives

A novel series of 1-((4-methyl-2-substituted thiazol-5-yl)methyleneamino)-2-substituted isothiourea derivatives was synthesized by alkylation of (Z/E)-1-((4-methyl-2-substituted thiazol-5-yl)methylene)thiosemicarbazide with alkylhalide in acetone. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, and mass spectrometry) methods. The newly synthesized compounds were screened for in vitro antimicrobial activity. Most of the compounds show moderate to excellent antimicrobial activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.]     

Facile Synthesis of 2-Substituted cis-2-cyclopentene-1,4-diol Derivatives

2-Substituted cis-2-cyclopentene-1,4-diol derivatives are used as starting materials for prostaglandin synthesis¹. Two papers concerning the synthesis of these compounds have been published so far ^1,2. In this paper we would like to present an alternative method for synthesis of 2-substituted cis-2-cyclopen-tene-1,4-diols from easily available cis-2-cyclopentene-1, 4-diol diacetate 1 ³.     

Synthesis and biological activity of novel 4- and 6-(1-alkyl/aryl-1H-benzimidazol-2-yl)benzene-1,3-diols

Abstract  

A one-pot synthesis of new biologically active 4- and 6-(1-alkyl/aryl-1H-benzimidazol-2-yl)benzene-1,3-diols has been developed. The compounds were obtained by the reaction of aryl-modified sulfinylbis[(2,4-dihydroxyphenyl)methanethione] with N-substituted benzene-1,2-diamines. Elemental analysis, IR, ¹H NMR, ¹³C NMR, and mass spectral data were used to elucidate their structures. The developed method offers short reaction times, easy and quick isolation of the products, and good yields. The antiproliferative properties of the synthesized compounds were investigated against a panel of human cancer cell lines. Some of the tested compounds showed significant cytotoxic activity.     

Synthesis of N-(3- and 4-substituted phenyl)-O-isobutyl thionocarbamates from O-isobutyl xanthate and amines using a nano-platinum multi-walled carbon nanotube catalyst

Abstract  

Twelve N-(3- and 4-substituted phenyl)-O-isobutyl thionocarbamates, eight of which are novel, were synthesized from O-isobutyl xanthate and 3- and 4-substituted anilines in the presence of a nano-platinum aminophenyl modified multi-walled carbon nanotube catalyst. The nano-Pt catalyst was prepared on a carbon nanotube support modified by diazotization, nitro group reduction, and subsequent microwave-assisted nano-Pt precipitation. The catalyst was characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, thermogravimetric analysis, and transmission electron microscopy. The nano-platinum/modified carbon nanotube catalyst was compared with a commercial Pt/active carbon catalyst in terms of product purity and yield. The results obtained by the use of the catalysts were additionally compared with those obtained by reaction of sodium isobutyl xanthogenacetate and 3- and 4-substituted anilines. Full structure characterization of the synthesized N-(substituted phenyl)-O-isobutyl thionocarbamates was achieved using FT-IR, ¹H and ¹³C NMR, and mass spectrometric methods, and their purity was proved by elemental analysis and gas chromatography. The new catalytic method offers advantages over the commercial method, such as higher yields and no product purification is required, thus conforming to the principles of ecologically friendly syntheses.     

Synthesis of C(2)Halomethyl Substituted Derivatives of 2,3-Dihydro-1,3-benzoxaz-4-ones

In the pursuit of biologically active compounds we required as a key intermediate 2,3-dihydro- 1,3-benzoxaz-bones having a halomethylene moiety at C(2), i.e. 3 (R₂ = H or alkyl, R₃ = CH₂X). The standard procedure for the preparation of this class of compounds is the condensation of salicylamide derivatives 1 with the proper aldehyde^1-5 and ketone^5,6. Usually, hydrochloric acid or sulphuric acid is used as catalyst and the water formed is cocornmittently removed using a dehydrating agent or by azeotropic destillation⁷. These procedures did not serve our purpose as the required α-substituted aldehyde or ketone as such is unstable under the conditions employed. Here we report that employment of acetals and ketals 2 affords the desired compound 3; yields are appreciable when the proper reaction conditions are used.     

Synthesis of 1-trifluoroacetyl-3-dialkylamino-methyl-5-monosubstituted benzimidazoline-2-thiones using trifluoroacetic acid as an acylating agent

1-Trifluoroacetyl-3-dialkylaminomethyl-5-monosubstituted benzimidazoline-2-thiones have been synthesized from p-substituted anilines which were acetylated with trifluoroacetic acid. The trifluoroacetanilides were nitrated, reduced and cyclised with carbon disulphide in the presence of alcoholic potassium hydroxide and finally treated with formaldehyde and suitable secondary amines to afford the Mannich bases. The compounds were characterised by their analytical and spectral (ir, pmr, ¹⁹F and mass) data. The synthesized compounds have been screened for anti-inflammatory and analgesic activity and found to be active.     

超声法合成新型3-(5-氯/苯氧基-3-甲基-1-苯基-4-吡唑基)异噁唑N-取代苯基去甲去氢斑蝥酰亚胺衍生物

去甲去氢斑蝥素与取代芳胺反应得到了一系列N-取代苯基去甲去氢斑蝥酰亚胺, 再与5-氯/苯氧基-4-(α-氯-α-肟基甲基)-3-甲基-1-苯基吡唑甲酰基氯代肟发生1,3-偶极环加成反应生成一系列未见报道的3-(5-氯/苯氧基-3-甲基-1-苯基-4-吡唑基)异噁唑N-取代苯基去甲去氢斑蝥酰亚胺衍生物. 所合成化合物经元素分析, IR, ¹H NMR, ¹H-¹HCOSY, NOESY确证结构.     

2-Car-bethoxymethyl-4H-3,1-benzoxazin-4-one 6. Synthesis of some new 3-acylamino-4-oxaquinazolin-2-yl-acetic acid benzylamides as possible anticonvulsants

Alternative ways of synthesizing 3-atizino-4-o.roquinazolin-2-yl-acetic and propionic acid benzy1amides and their aryl derivatives were investigated. The conditions of conversion of the synthesized 2-substituted 3-aminoquinazolin-4-ones into the corresponding 2-hydroxypyrazolo-3-R-(5,1-bjquinazolin-9(]H) -ones were determined.The findings of a study of the anticonvulsant properties of the synthesized compounds are reported.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 229–234, February, 1994. Original article submitted October 21, 1993.     

Structure-odor relationships of α-santalol derivatives with modified side chains

(Z)-α-Santalol, which has a unique woody odor, is a main constituent of sandalwood essential oil. We investigated the structure-odor relationship of (Z)-α-santalol and its derivatives, focusing on the relationship between the structure of the side chain and the odor of the compounds. Various α-santalol derivatives (aldehydes, formates, and acetates) were synthesized from (Z)- and (E)-α-santalol, which were prepared from (+)-3-bromocamphor through modifications of a reported synthetic route. The Z- and E-isomers of α-santalols have different double-bond configurations in the side chain. Analogues with saturated side chains were also prepared from the corresponding α-santalols, and the odors of the all the prepared compounds were evaluated. We found that the odors of the Z-isomers (woody) were similar to those of the corresponding saturated compounds, but clearly different from the odors of the corresponding E-isomers (odorless, fresh, or fatty). These results indicate that the relative configuration of the side chain with respect to the santalane frame plays an important role in the odor of α-santalol. E-configuration in the side chain eliminates the woody odor character of α-santalol and its examined derivatives, whereas the Z-configuration or saturation of the carbon side chain does not.     

Phototransformations of Some 2-Substituted 4 H-Chromen-4-ones (4-Chromones) Related to the Antitumor Antibiotic Hedamycin

The 2-substituted 4 H-chromen-4-ones (4-chromones) 2 and 3 have epoxysubstituted side chains at C(2) resembling that of the antibiotic hedamycin (1). They were chosen as model compounds and subjected to photolysis either in the presence or in the absence of oxygen. The products obtained were isolated by repeated HPLC., and their structures were determined by spectroscopic methods, mainly ¹H- and ¹³C-NMR. Especially noteworthy are the oxygen dependent formation of the tertiary alcohols 11 and 12 as well as the transformation of the diepoxychromone 3 to the allylic alcohols 13 and 14 , the spiro compounds 15 and 16 , and the 2-ethylchromone 19 .