Structure and conversions of the condensation products of phenols with unsaturated carbonyl compounds

The reaction of 3,4-xylenol with crotonaldehyde leads to the formation of 2, 6, 7-trimethyl-4-(4, 5-dimethyl-2-hydroxyphenyl)chroman, whose structure is verified by IR and UV spectra, by the synthesis of the methyl and the benzoyl esters, and by the investigation of the conditions and the products of pyrolisis.The IR spectrum of a paste of IV in vaseline oil was recorded on a IKS-14 apparatus     

Structure and conversions of the condensation products of phenols with unsaturated carbonyl compounds

The reaction of 3,4-xylenol with crotonaldehyde leads to the formation of 2, 6, 7-trimethyl-4-(4′, 5′-dimethyl-2′-hydroxyphenyl)chroman, whose structure is verified by IR and UV spectra, by the synthesis of the methyl and the benzoyl esters, and by the investigation of the conditions and the products of pyrolisis.     

Method for the condensation of diacetylene with carbonyl compounds

Conclusions A new method is proposed for the condensation of diacetylene with carbonyl compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 690–692, March, 1972.     

Combined interpretation of chromatographic and mass spectral information in identifying condensation products of carbonyl compounds

The paper considers one of possible approaches to the combined application of chromatographic and mass spectral data, based on the preliminary estimation of retention indices using additive schemes. This algorithm is used to determine structures of isomers formed in the condensation of carbonyl compounds (acetone and cyclohexanone) under basic catalysis.     

Phosphazene base-catalyzed condensation of trimethylsilylacetate with carbonyl compounds

The t-Bu-P4 base was found to be an excellent catalyst for the condensation of trimethylsilylacetate or trimethylacetonitrile with carbonyl compounds to form functionalized alkenes and beta-enaminoesters were also synthesized by the condensation with formanilides.     

Extending the range of compounds amenable for gas chromatography-mass spectrometric analysis

Gas chromatography-mass spectrometry (GC-MS) suffers from a major limitation in that an expanding number of thermally labile or low volatility compounds of interest are not amenable for analysis. We found that the elution temperatures of compounds from GC can be significantly lowered by reducing the column length, increasing the carrier gas flow rate, reducing the capillary column film thickness and lowering the temperature programming rate. Pyrene is eluted at 287 degrees C in standard GC-MS with a 30 m x 0.25 mm I.D. column with 1-microm DB5ms film and 1-ml/min He column flow rate. In contrast, pyrene is eluted at 79 degrees C in our "Supersonic GC-MS" system using a 1 m x 0.25 mm I.D. column with 0.1-microm DB5ms film and 100-ml/min He column flow rate. A simple model has been invoked to explain the significantly (up to 208 degrees C) lower elution temperatures observed. According to this model, every halving of the temperature programming rate, or number of separation plates (either through increased flow rate or due to reduced column length), results in approximately 20 degrees C lower elution temperature. These considerably lower elution temperatures enable the analysis of an extended range of thermally labile and low volatility compounds, that otherwise could not be analyzed by standard GC-MS. We demonstrate the analysis of large polycyclic aromatic hydrocarbons (PAHs) such as decacyclene with ten fused rings, well above the current GC limit of PAHs with six rings. Even a metalloporphirin such as magnesiumoctaethylporphin was easily analyzed with elution temperatures below 300 degrees C. Furthermore, a range of thermally labile compounds were analyzed including carbamates such as methomyl, aldicarb, aldicarbsulfone and oxamyl, explosives such as pentaerythritol tetranitrate, Tetryl and HMX, and drugs such as reserpine (608 a.m.u.). Supersonic GC-MS was used, based on the coupling of a supersonic molecular beam (SMB) inlet and ion sources with a bench-top Agilent 6890 GC plus 5972 MSD. The Supersonic GC-MS provides enhanced molecular ion without any ion source related peak tailing. Thus, the lower GC separation power involved in the analysis of thermally labile and low volatility compounds is compensated by increased separation power of the MS gained from the enhanced molecular ion. Several implications of these findings are discussed, including our conclusion that slower chromatography leads to better analysis of thermally labile compounds.     

Anticorrosion properties of products of N-(2-Vinyloxyethyl)-1,2-ethylenediamine condensation with carbonyl compounds

N-(2-Vinyloxyethyl)-N′-cyclohexylidene-1,2-ethylenediamine and N,N′,N″-tris-[2-(2-vinyloxyethyl)-aminoethyl]hexahydro-1,3,5-triazine were synthesized by reactions of N-(2-vinyloxyethyl)-1,2-ethylenediamine with cyclohexanone and formaldehyde with yields of 91 and 90%, respectively. The IR and ¹H and ¹³C NMR spectral data and the results of studying their anticorrosion properties are given.     

Liquid chromatography-mass spectrometry identification of imidacloprid photolysis products

Photolysis of imidacloprid by near ultraviolet (UV) radiation was investigated using reversed phase liquid chromatography (RPLC) and liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) operated in the positive ion mode. The decomposition of imidacloprid by near UV light is first order with a half life of 10.18 h. Photo-degradation products of imidacloprid identified in this study included imidacloprid urea, imidacloprid olefin, and imidacloprid desnitro. A degradation pathway is proposed for imidacloprid from an examination of the product decay curves obtained in this monitoring study which was performed in a batch test mode.     

Synthesis of pyrylium salts by condensation of benzalacetophenone with aliphatic carbonyl compounds

The acid condensation of chalcone with aliphatic ketones, aldehydes, and -dicarbonyl compounds was studied for the first time. Tri- and tetrasubstituted pyrylium salts, including compounds containing functional substituents, were obtained.Translated from Khimiya Geterotsiklicheskih Soedinenii, No. 7, pp. 883–885, July, 1972.     

Synthesis of pyrylium salts by condensation of Β-chlorocinnamaldehydes with carbonyl compounds

A method is proposed for the synthesis of unsymmetrical unsubstituted pyrylium salts by condensation of -chlorocinnamaldehydes with methyl and methylene ketones and -dicarbonyl compounds in the presence of HClO₄ or Lewis acids. The probable scheme of the reaction is examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1031–1035, August, 1974.     

Phenylboronic acid mediated triple condensation reactions of phloroglucinol and unsaturated carbonyl compounds

[reaction: see text] A remarkable phenylboronic acid mediated triple condensation reaction of phloroglucinol (1,3,5-trihydroxybenzene) with a series of alpha,beta-unsaturated carbonyl compounds is reported. This experimentally simple reaction afforded novel C3-symmetric 2H-chromene derivatives. These derivatives represent structural analogues of the natural product xyloketal A, which has been reported to be a potent inhibitor of acetylcholine esterase.     

N-allylation and N-benzylation of 2-phenylindole and its condensation with carbonyl compounds

By allylation and benzylation of 2-phenyl- and 2-phenyl-3-formylindole, N-allyl- and benzyl-substituted indoles have been obtained. By condensation of 2-phenylindole with 2-formylfluorene, and also with 4-aza- or 3-methyl-2-azafluorenone, compounds containing fragments of the indole, fluorene, and azafluorenone systems have been synthesized. In the interaction of 2-phenylindole or indole with formaldehyde and 2,5-dimethylpiperidin-4-one, depending on the temperature, bis(2-phenylindol-3-yl)methane, (2,5-dimethyl-4-oxopiperidino)-(1-indolyl)methane, and bis(indol-3-yl)methane are formed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 29, No. 5, pp. 648–650, May, 1993.     

Structure of products of the reaction of 2-cyanoaziridine with carbonyl compounds

The structure of azimexone (3), the product of the reaction of 2-cyanoaziridine with acetone, was confirmed on the basis of¹H and¹³C NMR spectra. The formation of this product is accounted for by the -aziridinoalkylating action of an intermediate containing a good leaving iminoyloxy group. Similar reactions were observed for 1-chloromethylaziridine and a 1-aziridinylmethylammonium salt (6), but not for 1-methoxymethylaziridine (7) and 1-aziridinemethanol.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2136–2139, December, 1993.