| 摘要 |
PCT No. PCT/GB94/02397 Sec. 371 Date Jan. 11, 1996 Sec. 102(e) Date Jan. 11, 1996 PCT Filed Nov. 2, 1994 PCT Pub. No. WO95/12570 PCT Pub. Date May 11, 1995This invention provides improvements in certain processes for alkylating amino acids whereby yields based on amino acid are improved. More specifically, the invention provides a process for the preparation of amino acid derivatives in free acid or salt form, in which the nitrogen atoms of two or more amino acid molecules are linked by a hydrocarbyl or substituted hydrocarbyl group, which comprises reacting, in an aqueous medium at a pH in the range 7-14, a compound of the formula X-A-Y where X and Y are halo atoms which may be the same or different and A is a hydrocarbyl or substituted hydrocarbyl group, in which X and Y are attached to aliphatic or cycloaliphatic carbon atoms, with an amino acid (or salt thereof), wherein the reaction is carried out in the presence of dissolved cations of an alkaline earth metal or of a transition metal and/or wherein the unreacted amino acid is recovered and recycled.
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