反应详情

L(+)-tartaric acid disodium salt, also denoted as bisodium L-tartrate, is commercially available, e.g. from Sigma-Aldrich (CAS Number 6106-24-7). It is noted that instead of using L(+)-tartaric acid disodium salt, it is also possible to use L(+)-tartaric acid (commercially available from e.g. Sigma-Aldrich, CAS Number 87-69-4) and prepare the L(+)-tartaric acid disodium salt in situ, by addition of additional NaOH. The same holds for the other potential starting material, DL-tartaric acid disodium salt: it may be purchased from e.g. Sigma-Aldrich or produced in situ from DL-tartaric acid (CAS Number 133-37-9) or DL-tartaric acid monosodium salt and NaOH. In fact any tartaric acid source, containing D, L, meso in any proportion and in the acidic or salt form can be used for this process. D-tartaric acid can also be used as starting material, but this is less preferred because it is relatively expensive. The use of L-tartaric acid disodium salt (either produced in situ by addition of NaOH or used as such) is preferred because these starting materials are relatively cheap and the process to prepare a composition with between 55 and 90% by weight of meso-tartaric acid is faster than when a mixture of D- and L-tartaric acid is used as starting material. Obviously, it is also possible to use a mixture of D-, L-, and meso-tartaric acid.