Methylaniline isomers, separation

The graph shows that 2-methylaniline cannot be separated from 3-methyl aniline and that aniline can be separated from the methyl aniline isomers using an eluent concentration of 5 x 10 3 [H+]. The separation of 2-naphthyl amine from 1-naphthyl-amine can be carried out at 8 x 10 3 [H+] in less than 20 minutes. The separation of aniline and 2-methylaniline using 5 x 10 3 [H+] is shown in Figure 3. The concentration of aniline is 5 ppm while the 2-methylaniline is 10 ppm... 

Preparation of each geometrical isomer of the iV-methylaniline enamines is possible, since the intermediate diastereoisomeric adduct can be separated. It is a route to pure Z-isomers, which are very difficult to prepare by other means244 (equations 14 and 15). 

Enantiomeric separation of nonpharmaceutical compounds include IV-alkyl-Af-methylaniline W-oxides (ethyl to butyl plus isomers) on a Chiralcel OD column. (A = 210 nm) using 1% to 3% ethanol in hexane [143]. Carrea et al. [144] separated the enantiomers of various substituted chromium and magnesium tricarbonyl metallocenes ( / -benzene and -cyclopentadiene) on a Chiralcel OD column (A = 315 run) with an isocratic mobile phase that varied from 1% to 10% ethanol in hexane depending on the enantiomeric pair involved. Chromium tricarbonyl compounds complexed with a variety of ij -arenes were separated on a Whelk-O column (A = 315 nm) using a 20/80 IPA/hexane as the mobile phase [145]. 

Hadley et al. [143] separated six A -alkyl-A -methylaniline iV-oxides (ethyl to butyl and isomers) and their enantiomers on a Chiralcel OD colurrm (2 = 210nm) using 1.5-3.0% ethanol in hexane as the mobile phase. Results are tabulated for each solute and its enantiomer. Nearly complete resolution of all 12 compounds was achieved in one chromatographic run, but only after extremely long chromatographic run times (>240 min). Separation of individual enantiomeric pairs was more effective with most analyses completed in <40 min. 

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