Tetrabutylammonium hydroperoxide

Treatment of the crude reaction mixture containing compounds 718, 719 and ferrocene without purification with benzoyl chloride (70 °C) followed by hydrolysis of the resulting benzoylated pyrrole 720 using tetrabutylammonium hydroperoxide (TBAH) furnished pharmaceutical agent (6 )-Ketorolac (ToradoT and Acular, 721, ee 90% determined by chiral HPLC, 25% isolated yield over three steps) along with recovered chiral auxiliary. 

Abbreviations p, ratio between ionic radii of cation and anion TBHP, rm-butyl hydroperoxide EBHP, ethylbenzene hydroperoxide PO, propylene oxide TBOT, tetrabutyl orthotitanate TEOT, tetraethyl orthotitanate TIOT, tetraisopropyl orthotitanate TEOS, tetraethyl orthosilicate THF, tetrahydrofuran TPA-OH, tetrapropylammonium hydroxide TMOS, tetramethyl orthosilicate TBA-OH, tetrabutylammonium hydroxide TBP-OH, tetrabutylphophonium hydroxide TEA-OH, tetraethylammonium hydroxide TMA-OH, tetramethylammonium hydroxide. 

The system, 2-pyrazinecarboxylic acid (54) + tetrabutylammonium metavanadate [(Bu4N)V03] + hydrogen peroxide, in acetonitrile at 0°C induced effective oxidation of alkanes or cyclohexane to hydroperoxides, alcohols to aldehydes or ketones, and aromatic hydrocarbons to phenols.11101715... 

MTBE methyl tertiary-butyl ether PO propylene oxide SAPO silico-aluminophosphate SBU secondary building unit SDA structure-directing agent TBAOH tetrabutylammonium hydroxide TBHP a -butyl hydroperoxide TBOT tetrabutyl orthotitanate TEA tetraethylammonium... 

Nitrothiophene undergoes nucleophilic hydroxylation by applying potassium terf-butyl hydroperoxide, probably via a vicarious nucleophilic substitution (VNS) process. The only product was a rather unstable 3-hydroxy-2-nitrothiophene potassium salt, which could be converted into the more stable tetrabutylammonium salt (Scheme 105) [165]. 

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