| 摘要 |
Isododecanol prepn. by Guerbet condensn. of n-hexanol in an alkaline medium takes place by using an initial mixt. contg. 10-40 wt.% residue from a previous Guerbet condensn. in addn. to n-hexanol. The added residues can originate from the Guerbet condensn. of an alcohol other than n-hexanol. Pref. catalyst is a 17% Ni powder suspension in fatty acid, prepd. by reducing Ni formate with H2 at 280 degrees C. Other suitable catalysts are Raney-Ni, Girdler-Ni G 49, Pb silicate and Cu-Fe catalysts, esp. a mixt. of Fe2(SO4)3 and CuCO3.Cu(OH)2 in ratio 1 : 1. At atmos. pressure, reaction temp. is above 100 degrees C. Good results are obtd. with reflux temps. 150-250 degrees C. Alkali quantity used is 3-8 wt.% calculated as pure alkali hydroxide w.r.t. n-hexanol. Residue addn. improves yields, e.g. from 79.8- to 91.5% of theoretical, and reduces residue formation, e.g. from 244- to 111 g. |
