The X-ray crystal structures of three tricyclic neuroleptics have been
completed and are reported herein. These include amitriptyline hydroc
hloride (I), chlorprothixene hydrochloride (II), and ethopropazine hyd
rochloride (III). The structures were compared with the structures of
similar molecules with similar pharmacological activity. It was found
that there is a great deal of flexibility in the structures of these m
olecules, which makes it difficult to determine the pharmacologically
active conformations. Crystallographic data: (I) C20H24NCl, monoclinic
space group P2(1)/a, a = 13.812(4) Angstrom, b = 9.140(2) Angstrom, c
= 14.345(4) Angstrom, beta = 96.82(2)degrees, Z = 4, final R = 0.059
for 1630 observed (I > 3 sigma(I)) reflections. (II) C18H20NSCl2.CHCl3
, monoclinic space group C2/c, a = 29.416(4) Angstrom, b = 6.986(1) An
gstrom, c = 23.374(3) Angstrom, beta = 109.78(1)degrees, Z = 8, final
R = 0.046 for 1436 observed reflections. (III) C19H25N2SCl, monoclinic
space group P2(1)/c, a = 8.849(1) Angstrom, b = 14.475(2) Angstrom, c
= 14.832(1) Angstrom, beta = 98.72(1)degrees, Z = 4, final R = 0.039
for 2583 observed reflections.