Zinc butyl ethyl , reaction

The butyl alcohol is pumped from storage to a steam-heated preheater and then to a vaporiser heated by the reaction products. The vapour leaving the vaporiser is heated to its reaction temperature by flue gases which have previously been used as reactor heating medium. The superheated butyl alcohol is fed to the reaction system at 400°C to 500°C where 90 per cent is converted on a zinc oxide-brass catalyst to methyl ethyl ketone, hydrogen and other reaction products. The reaction products may be treated in one of the following ways ... 

Neither reaction excludes the other, nor are these the only routes possible. The oxidation of alkylanions on a metallic anode is likely. Other processes are more clearly indicated when, instead of Cd, Zn is used as a cathode. In the latter case, zinc alkyls R2Zn and RZnI are formed by cathodic reaction of RI. This allows an efficient preparation of R4M where M = Pb, Sn and R = propyl, butyl or pentyl39, in contrast to the cathodic reduction of alkyl halides which is practically limited to the methyl and ethyl groups. 

Butylphenyl thioether is first prepared by the interaetion of sodium benzenethiolate and butyl chloride. The resulting product on treatment with benzoyl ehloride and aluminum chloride yields butyl-p-benzoyl phenyl thioether. This on reaction with zinc and sodium hydroxide and earbonyl ehloride yields an intermediate. The intermediate on treatment with thiourea, sodium hydroxide, 2-dimethyl amine ethyl chloride and hydrochloric acid gives rise to the desired eompoimd. 

Tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate antioxidant, textiles Calcium disodium EDTA antioxidant, thermoplastic elastomers Pentaerythrityl tetrakis (P-laurylthiopropionate) antioxidant, thermoplastic rubber p-Cresol/dicyclopentadiene butylated reaction product Zinc diisobutyidithiocarbamate antioxidant, thermoplastics N-Pelargonoyl-p-aminophenol Stearoyl p-aminophenol antioxidant, tobacco Ethyl maltol... 

Protection and Deprotection.—N-Protected a-amino-acids are readily esterified by methanol or ethanol in 60—80% yield after reaction with an enamine (e.g. from isobutyraldehyde and piperidine) and t-butyl isocyanate. Such amino-acids can also be esterified efficiently with alkyl halides under phase-transfer conditions with no racemization. Direct esterification of a-amino-acids with ethyl toluene-p-sulphonate in boiling ethanol gives a-amino-acid ethyl esters in 80—90% yield as the sulphonate salts. The protection of acid functions by formation of the 2-chloro-(or bromo-)ethyl esters has been discussed. These derivatives survive exposure to both moderately acidic and basic conditions and are removable by conversion into the iodoethyl analogues followed by zinc reduction. Alternatively, they may be converted into hydrophilic ammonium or phosphonium salts which exhibit enhanced acid stability but which are cleaved by very dilute base. Yet another method for the removal of such groups using supernucleophilic Co phthalocyanin anions has been reviewed. Further routes to 2,2,2-trichloroethyl esters have been described, one of which employs an activated ester intermediate and is suited to acid-labile substrates. 

A one-carbon homologation of aldehydes and ketones to carboxylic acids has been reported to involve the Horner-Emmons modification of the Wittig reaction using diethyl-/er/-butoxy(cyano)-methylphosphonate (EtO)2 P0CH(CN)0/-Bu to produce ethyl-/pr/-butoxyacrylonitriles. The /er/-butyl ether group is cleaved by zinc chloride in refluxing acetic anhydride, and the a-acetoxyacrylonitrile is converted to the acid by solvolysis. 

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