| abstract |
Monocrystalline DL - cysteine suitable, e.g. for permanent wave solns. or medical prod. raw material, has an X-ray diffraction pattern with reflection lines with a relative intensity of, e.g. 0.57, 0.34, 0.44 and 1.00 respectively at lattice spacings of 11.90 Angstrom, 5.97 Angstrom, 3.97 Angstrom and 2.98 Angstrom, displays good storage stability and is pptd. by suspending or dissolving a DL - cysteine hydrochloride or aromatic sulphonate in a mixt. of 5-60 wt.%, pref. 10-50 wt.% water and a lower, pref. 1-4C alcohol or cellosolve and neutralising at -20 - 80 deg.C with a base, e.g. C2H4NH2, C5H5N, LiOH or BaCO3. |