Quantitative micro determination of alcohols as esters of pyruvic acid 2,6-dinitrophenylhydrazone

N-Methylimidazole as a catalyst for analytical acetylations of hydroxy compounds

“…Sublimation is a very useful method for purifying analytical reagents or reference standards, separating solid mixtures into constituents, and concentrating very small traces of impurities in a solid substance (1). Recently, vacuum sublimation behavior of various metal chelates of 8-hydroxyquinoline (2), phthalocyanine (3), and /3-diketones with aliphatic groups (acetylacetone (4-8) and dipivaloylmethane (6)) and fluoromethyl groups (trifluoroacetylacetone (6), hexafluoroacetylacetone (6), benzoyltrifluoroacetone (7), thenoyltrifluoroacetone (7), and monothiothenoyltrifluoroacetone ( 9)) has been investigated, and many metal chelates are isolated and purified with the use of the vacuum sublimation method. Radiochemical and hot-atom chemical studies on metal chelates of phthalocyanine (10) and /3-diketones with acetylacetone (11,12) and dipivaloylmethane (13)(14)(15) have also been carried out by means of the vacuum sublimation technique.…”

“…Schenk et al (6) studied various tertiary amines as catalysts for the acetylation of cyclohexanol with acetic anhydride, and found triethylenediamine to be about 50 times more effective than pyridine. This compound is also superior to pyridine in catalyzing the acylation of alcohols with the acid chloride of the 2,4-dinitrophenylhydrazone of pyruvic acid (7).…”

Retention of aliphatic alcohols by anhydrous lactose

“…Phenylhydrazones. Qualitative indication of retention of alcohols by the resulting anhydrous «-lactose was obtained by formation of the pyruvate 2,6-dinitrophenylhydrazone esters of the alcohol, and the alcohol was identified by thin-layer chromatographic comparison with authentic derivatives (Schwartz, 1970). Attempts to use this reaction for quantitative analyses of the alcohol contents of the lactose samples proved unsatisfactory, the measured percentage of alcohol decreasing with increasing sample size.…”

“…These samples were weighed initially and after heating to temperatures just below and just above the onset of fusion. Pyruvic acid chloride 2,6-dinitrophenylhydrazone was used to form ester derivatives of the alcohols associated with the lactose samples for the purpose of qualitative and quantitative analyses (Schwartz, 1970).…”