Distillation distn

To save space the following abbreviations have been generally used in Chapters 3, 4 and 5 abs (absolute), anhyd (anhydrous), aq (aqueous), atm (atmospheric), crystd (crystallised), crystn (crystallisation), crysts (crystallises), dec (decomposes), dil (dilute), distd (distilled), distn (distillation), evap (evaporate), evapd (evaporated), evapn (evaporation), filtd (filtered), h (hour[s]), pet ether (petroleum ether, ligroin), ppte (precipitate), ppted (precipitated), pptn (precipitation), satd (saturated), soln (solution), TLC (thin layer chromatography), HPLC (high pressure liquid chromatography), vac (vacuum), vol (volume). Other abbreviations used occasionally are self evident in meaning. 

Titles of periodicals are defined as in the Chemical Abstracts Service Source Index (CASSI), except that full stops have been omitted after each abbreviated word. Abbreviations of words in the texts of Chapters 4, 5 and 6 are those in common use and are self evident, e.g. distn, filtd, cone and vac are used for distillation, filtered, concentrated and vacuum. 

Rapid procedure Dry over anhydrous K2CO3 for 24h, followed by further drying for 24h over 3A molecular sieves or boric anhydride, followed by distn. Alternatively, stir over P2O5 (5% w/v) for 24h then distil. However this last method is not suitable for use in reactions with very acid sensitive compounds. 

Conductivity grade benzonitrile (specific conductance 2 x 10" mho) was obtained by treatment with anhydrous AICI3, followed by rapid distn at 40-50° under vacuum. After washing with alkali and drying with CaCl2, the distillate was vac distd several times at 35° before being fractionally crystd several times by partial freezing. It was dried over finely divided activated alumina from which it was withdrawn as required [Van Dyke and Harrison J Am Chem Soc 73 402 7957]. 

Bromoindole [10075-50-0] M 196.1, m 90.5-91°, 90-92°, pK 16.13 (NH). Purified by steam distn from a faintly alkaline soln. Cool the aqueous distillate, collect the solid, dry in a vacuum desiccator over P2O5 and recryst from aqueous EtOH (35% EtOH) or pet ether-Et20. MeOH 279, 287 and 296 (loge... 

Purification methods described for the mixed isomers are applicable. The individual isomers can be separated by very efficient fractional distn, followed by fractional crystn by partial freezing. The cz5-isomer reacts preferentially with AICI3 and can be removed from the /ranj-isomer by stirring the mixture with a limited amount of AICI3 for 48h at room temperature, filtering and distilling. 

Vacuum distn at 60-65°/15mm, discarding the first 5-10%, was followed by dilution with an equal volume of freshly distilled water at 70-75°, using magnetic stirring under nitrogen. The soln is stored at low temp (3-4°),... 

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