184 research outputs found
Iodine Substitution Products of Vanillin
In 1872 Carles prepared a mono- and a diiodovanillin, but did not characterize them. In the current edition of Beilstein they are recorded as of unknown structures. Carles\u27 work has now been repeated, and the structures of his products have been shown to be 5-iodovanillin and 2, 5-diiodovanillin, respectively. The behavior of these and similar derivatives toward typical amino compounds has been studied. No pronounced steric hindrance was noted in the latter reactions. The relation between the numerical values of the melting points and the positions of the halogen atoms in the iodine derivatives, so far as they have been obtained, is in good agreement with that observed in the cases of the chlorine and bromine compounds, viz., that the lowest value is found for position 2, the next higher for 5 and the highest for 6. Likewise, for a given position the lowest is found for the chloride, the next higher for the bromide and the highest for the iodide
The use of 2-Chlorophenoxyacetyl Chloride in the Preparation of Mixed Diacyl Derivatives of Ortho Aminophenols
Raiford and coworkers (1) have proved by a long series of experiments that when two acyl radicals, R-Ć=O and R\u27-Ć =O, are introduced into an ortho aminophenol only one mixed diacyl derivative can generally be obtained, regardless of the order of introduction of the radicals; and in this product the heavier and more acidic of these groups is usually found attached to nitrogen. To meet this requirement the migration of acyl from nitrogen to oxygen must occur in one of these reactions. If the acyls are R-Ć=O and R-0-Ć=O the latter is most frequently found on nitrogen
Action of Thionyl Chloride on Urethanes (Abstract)
Raiford and Shelton [J. Org. Chem., 4, 207 (1939)] found that hot pyridine causes 2-carbophenoxyamino-4-methy 1-6-bromophenyl p-tolylsulfonate to lose phenol and give a condensation product which was found to be a 1,3- derivative of uretedione (uretidone). This type of derivative was also obtained by Warren and Wilson [Ber., 68, 957 (1935) J by the action of thionyl chloride on phenylurethane. But it has now been found that the last-named reaction is specific for phenylure thane. When the phenyl radical contains a negative substituent, thionyl chloride causes no action after five hours refluxing. If the substituent is alkyl the treatment causes tar formation, from which nothing definite could be isolated. Ethyl and n-butyl carbamates react with thionyl chloride to give the corresponding esters of allophanic acid and small amounts of cyanuric acid. Under the same treatment 2-naphthylurethane undergoes chlorination to give the 1-chloro derivative, while the 1-naphthyl compound gives the 4-chloro derivative
Condensation of Vanillin and Substitution Products with Hippuric Acid (Abstract)
Condensation of vanillin with hippuric acid in presence of acetic anhydride gives a-benzoylamino-3-methoxy-4-acetoxycinnamic acid which, under the conditions of the experiment, loses the elements of water to give the related azlactone. This view of the reaction is supported by the fact that when esters of hippuric acid are used in this condensation lactones are not obtained. The ring may be opened by warming the lactone with 3 N caustic alkali solution. More drastic treatment causes further hydrolysis with the loss of benzoic acid and ammonia, and gives the related pyruvic acid. Similar results were obtained by starting with aceturic instead of hippuric acid. Several substitution products of vanillin were tested
Oxidation of Pyrazolines Obtained from Unsymmetrical Dibenzalacetones
When the hydrazone of an unsymmetrical dibenzalacetone rearranges to the isomeric pyrazoline two products are theoretically possible. The identification of these products is somewhat difficult. In previous work in this Laboratory1 the pyrazolines have been oxidized by aqueous alkaline permanganate solution and the substituted pyrazole and benzoic acids, respectively, separated and identified. The yields are small due to the fact that the permanganate is known to degrade some members of both these groups further.2 In the present work the ketones used contained substituted vanillal residues, and the oxidation was done in pyridine solution. The yields were much higher than those previously obtained
Bromination of Methyl-4-Acetylaminophenyl Ketone
Bromination of a water or acetic acid solution of methyl-2-acetylaminophenyl ketone gives a nuclear substitution product ; with dry material or in the presence of concentrated sulfuric acid, halogen enters the side chain, Baeyer and Bloem [Ber., 17, 963 (1884)]. With methyl-4-acetylaminophenyl ketone it has been found in this laboratory that the highest yield of nuclear bromide is obtained by allowing 1.84 molecular proportions of bromine, dissolved in 19.8 volumes of glacial acetic acid to drop during a period of twenty minutes into a solution containing one molecular proportion of the ketone dissolved in 20 times its weight of 50% acetic acid, while the mixture is shaken and the temperature kept at 20-21 ° , and the whole allowed to stand for 3¾ hours. When water is not present, substitution usually takes place in the side chain. This work has been done in order to identify products obtained in the study of the condensation reactions of methyl-4-aminophenyl ketone
Efficacy of the Young Women's CoOp: An HIV Risk-Reduction Intervention for Substance-Using African-American Female Adolescents in the South
HIV/sexually transmitted infection (STI) risk-reduction interventions are needed to address the complex risk behaviors among African-American female adolescents in disadvantaged communities in North Carolina. In a two-group randomized trial, we reached 237 sexually active, substance-using African-American female adolescents, to test a risk-reduction intervention, the Young Women’s CoOp (YWC), relative to a nutrition control. In efficacy analyses adjusting for baseline condom use, at three-month follow-up participants in the YWC were significantly less likely to report sex without a condom at last sex relative to control. There were mixed findings for within-group differences over follow-up, underscoring the challenges for intervening with substance-using female youths
International Trade and Investment Sanctions
The purpose of this paper is to clarify the theory of international economic sanctions and to provide estimates of the short-run economic impact on South Africa of externally imposed reductions of the imports and capital flows into that country. A macroeconomic picture of South Africa's "dependence" is drawn, and the economy's vulnerability in the short run is seen to be in its capacity to import, not in exports or capital flows. Trade and capital sanctions most clearly damage South Afnca's growth potential; the short-run impact is harder to quantify. A static linear programming model of the South African economy is constructed in an attempt at this quantification. This model estimates that small sanctions would have small impact—i.e., if imports were reduced by less than one-fourth, GDP would be cut by only about one half as large a percentage as imports. Larger import reductions cause greater damage. If imports were to be cut in half, not only would GDP be seriously reduced but massive unemployment and relocation of white labor would occur.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68182/2/10.1177_002200277902300401.pd
Between Pixels And Play: The Role of the Photograph in Videogame Nostalgias
The histories of videogames are so often contained with nostalgia for the screen, for the arcade, console, computer or game box design, and for the experience of playing itself. Various amateur photographs now archived on Flickr allow us to remember beyond the stereotypical, albeit iconic, imagery of Pac-Man and Space Invaders. The essence of play becomes captured in the photograph as a “collective memory” and “reflective nostalgia” for the places, times and actions inherent in the histories of the early 1970s and 1980s videogame era. It is through debating the so-often implied “reconstructed nostalgias” offered by videogame companies to consumers in their remakes of classic game titles that this paper explores “reflective nostalgia” of videogames by examining the role of photographs taken during the act of playing these games. In doing so it reframes 1980s videogame nostalgias beyond the “mediated space” of the screen, and moves instead towards the “play space” as another way of keeping these histories alive
Patterns of dog gastrointestinal contractile activity monitored in vivo with extraluminal force transducers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44363/1/10620_2005_Article_BF02233437.pd
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