| 摘要 |
<p>Omega-amino-dodecanoic acid (I) is recovered by sepg. the by-products from the crude acid by, (a) treatment with an acid (II) in molar ratio (II):(I), of between 2 and 1:1, pref. 1.5:1, in the presence of sufficient water to dissolve at least part of the resultant salt without dissolving most of the by-products in the crude; (b) sepg. the 2 phases formed into one contg. (II) and the amino acid salt, and one contg. most of the by-products; (c) decomposing the salt with an (in)organic base (III) and then isolating the free amino acid obtd. Used in the prodn. of (I), partic. by redn. of 11-cyano-undecanoic acid and subsequent purificn. by crystallisation, amts. of (I) remaining dissolved in the mother liquor can be recovered, leading to yields of 90-95% compared with 85%.</p> |
