3 resultados para Sodium borohydride

em Brock University, Canada


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This research was directed towards the investigation and development of an aryne route to the syntheses of aporphi ne and dibenzopyrrocolinium (dibenzoindolizinium) alkaloids and to the stability of the latter under the conditions used for aryne formation. The work c an be divided into three main sections . i) - Synthesis of Glaucine 6-Bromo-3,4-dimethoxyphenylacetic acid, prepared by the action of bromine i n acetic acid on3,4-dimethoxyphenylacetic a cid, was converted into its acid chloride by t he action of thionyl chloride. This on treatment with 3,4- dimethoxyphenylethylamine pr ovided N-(3, 4-dimethoxyphenylethyl)- 2-(2-bromo-4,S-dimethoxyphenyl)-acetamide which on dehydration with phosphoryl chloride (Bischler Napieralski reaction) in dry benzene afforded l -(2-bromo-4,S-dimethoxybenzyl)- 3,4-dihydro-6,7-dimethoxyisoquinoline, isolated as hydrochl oride. A new method o f destroying the excess of phosphoryl chloride was developed which proved to be quite useful. Methylation of the dihydroisoquinoline'with methyl iodide in methanol , and subsequent reduction with sodium borohydride provided (±)-6-bromolaudanosine. Act ion of potassamide or sodamide in anhydrous liquid ammonia on (±)-6-bromolaudanosine yielded the corresponding amino derivative along with other products. Diazotization and ring closure of (±)-6-aminolaudanosine then a f forded (±)-glaucine which was isolated as methiodide. ii) - Intramolecular Capture of Aryne During Glaucine Synthesis, and Subsequent Reactions . This section deals with the by-products formed under the conditions of the aryne stage of t he glaucine synthesis. The crude product, obtained in the reaction of potassamide or sodamide in liquid ammonia on (±)-6-bromolaudanosine, was s eparated by chromatography, Three products were separated and identified. a ) - 5,6-Dimethoxy-2-( 3,4-dimethoxy-6-ethylphenyl)-lmethylindole. Two mechanisms are proposed for the formation of this interesting product. This compound also was prepared by the action of potassamide in l,iquid ammonia on 5,6 ,l2,l2atetrahydro- 2,3,9,lO-tetramethoxy-7-methyldibenz[b,g]indolizinium i odide . b) - 5,6-Dimethoxy-2-(3,4-dimethoxy-6-vinylphenyl)-lmethylindoline. Its formation represented a new method of Hofmann degradation . Further confirmation of structure was done by performing the normal Hofmann reaction on 5, 6,12,12a-tetrahydro -2/3,9,lO-tetramethoxy ~7-methyldibe nz[ b,g]indolizinium iodide. The indoline prepared i n this way was identical in all respects with that prepared above . c) - 1- (2-amino-4,5-dimethoxybenzyl ) -l,2,3,4-tetrahydro-2- methyl-6,7-dimethoxyisoquinoline, was converted t o glaucine as stated in section 1 . iii) - Attempt:,ed Sxnthesis of Liriodenine Piperonal was converted into 3,4-methylenedioxyinitrostyrene which on reduction with lithium aluminium hydride provided 3,4-methylenedioxyphenylethylamine. The method of extraction after the reduction was improved t o some extent. The amine on condensation with m-chlorophenylacetyl chloride, prepared by the action of oxalyl chloride on 3,4-methylenedioxyphenylacetic acid, provided N-[ ~ -(3,4-methylenedioxyphenyl)- e thyl)-3-chlorophenylacetamide. This on dehydration with phosphoryl chloride in dry benzene followed by air oxidation afforded l-(3-chlorobenzoyl)-6,7-methylenedioxyi soquinoline. This compound on r eaction with potassamide in liquid ammonia afforded a crude product from which. one product was separated by chromatography i n a pure condition . This yellow compound analysed as,c17Hl ON2021 and was t he main product i n the reaction ; a t entative structure is proposed. A second compound, not obtained in pure condition, was submitted to Pschorr reaction in the hope of obtaining liriodenine, but without success.

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The algebraic expressions for the anharmonic contributions to the Debye-Waller factor up to 0(A ) and 0 L% ) £ where ^ is the scattering wave-vector] have been derived in a form suitable for cubic metals with small ion cores where the interatomic potential extends to many neighbours. This has been achieved in terms of various wave-vector dependent tensors, following the work of Shukla and Taylor (1974) on the cubic anharmonic Helmholtz free energy. The contribution to the various wave-vector dependent tensors from the coulomb and the electron-ion terms in the interatomic metallic potential has been obtained by the Ewald procedure. All the restricted multiple whole B r i l l o u i n zone (B.Z.) sums are reduced to single whole B.Z. sums by using the plane wave representation of the delta function. These single whole B.Z. sums are further reduced to the •%?? portion of the B.Z. following Shukla and Wilk (1974) and Shukla and Taylor (1974). Numerical calculations have been performed for sodium where the Born-Mayer term in the interatomic potential has been neglected because i t is small £ Vosko (1964)3 • *n o^er to compare our calculated results with the experimental results of Dawton (1937), we have also calculated the r a t io of the intensities at different temperatures for the lowest five reflections (110), (200), (220), (310) and (400) . Our calculated quasi-harmonic results agree reasonably well with the experimental results at temperatures (T) of the order of the Debye temperature ( 0 ). For T » © ^ 9 our calculated anharmonic results are found to be in good agreement with the experimental results.The anomalous terms in the Debye-Waller factor are found not to be negligible for certain reflections even for T ^ ©^ . At temperature T yy Op 9 where the temperature is of the order of the melting temperature (Xm) » "the anomalous terms are found to be important almost for all the f i ve reflections.

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A double-blinded, placebo controlled, cross-over design was used to investigate sodium citrate dihydrate (Na-CIT) supplementation improve 200m swimming performance. Ten well-trained, male swimmers (14.9 ± 0.4y; 63.5 ± 4kg) performed four 200m time trials: acute (ACU) supplementation (0.5g/kg), acute placebo (PLC-A), chronic (CHR) (0.1g/kg for 3 days and 0.3g/kg on the 4th day pre-trial), and chronic placebo (PLC-C). Na-CIT was administered 120min pre-trial in solution with 500mL of flavored water; placebo was flavored water. Blood lactate, base excess (BE), bicarbonate, pH, and PCO2 were analyzed at basal, 100min post-ingestion, and 3min post-trial via finger prick. Time, lactate, and rate of perceived exertion were not different between trials. BE and bicarbonate were significantly higher for the ACU and CHR trials compared to placebo. “Responders” improved by 1.03% (P=0.043) and attained significantly higher post-trial lactate concentrations in the ACU versus PLC-A trials and compared to non-responders in the ACU and CHR trials.