H2O-AcOH

Methoxycarbonylmethyl-2(l//)-quinoxalinone (220) with p-chlorobenzene-diazonium chloride gave a product, initially formulated as 3-[a-(p-chloro-phenylazo)-a-methoxycarbonylmethylene]-3,4-dihydro-2(l//)-quinoxalinone (221) but later as the tautomeric 3-[a-(p-chlorophenyUiydrazono)-a-methoxy-carbonylmethyl]-2(l//)-quinoxalinone (222) (HCl, H2O, AcOH, <5°C, 10 min, then 95°C, 30 min 90%). ° Such tautomerisms have been studied in some detail.(See also Section 6.6.)... 

Spectroscopic Studies of the Organic Cycles of Carbonylation Reactions 219 MeOAc + H2O AcOH + MeOH (3)... 

Low water level in the reaction medium which simplifies the separation train especially for the HI-H2O-ACOH mixture... 

Substrate cf3co2h 97 wt % (CF3)2CHOH 97 wt % CF3CH2OH 70 wt % hco2h cf3ch2oh h2o AcOH 50% EtOH 80% EtOH EtOH... 

The diethanolamine linker 1.13 (70), obtained from aminomethyl PS resin and ethylene oxide, has been used to support boronic acids which, after SP transformations, were released with THF/H2O/ACOH 18/1/1 in 1 h at rt or, when acid-labile boronic acids were involved, with THF/H2O 9/1 in 2 h at rt. 

Yang et al. used catechol to immobihze borane and boronic acids [58], since support-bound boronic catachol ester hnkage is stable enough to perform amidation reactions. Custom-derivatized boronic acids could be obtained, which could be hberated from the support with THF/H2O/ACOH 90 5 5 (v/v/v). Hebei et al. reported Suzuki-mediated release of biaryls from polyglycerol esters of various boronic acids and aryl bromides [59]. 

The 3-chloro derivative was developed to impart greater acid stability to the azido-benzyl ether. It is formed using the benzyl bromide (NaH, DMF) and is much more stable to BF3-Ft20, but it is cleaved in neat TFA. Conditions used to cleave the azi-dobenzyl ether also cleave the 4-azido-3-chlorobenzyl ether (Ph3P, THF DDQ, H2O, AcOH, rt, 1 h, 75% yield). The ClAzb ether is inert to DDQ oxidation. ... 

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