3,4-Dichloro-5-(6-chloro-9-(4-fluorobenzyl)-9
H-purin-8-yl)isothiazole, a novel purine
derivative, was synthesized by the cyclization of pyrimidine amine. Its
structure was characterized by
1H NMR,
13C NMR,
19F
NMR, H RMS and single-crystal X-ray diffraction. This compound
3 is crystallized from a mixed solvent
of dichloromethane and
n-hexane (1:2,
v/v) for structural identification as monoclinic crystal system, space group
P2
1/
n with
a = 11.66250(10),
b = 8.21300(10),
c = 17.77920(10) Å,
V = 1676.34(3) Å
3,
Z = 4,
Dc = 1.643
g/cm
3,
F(000) = 832.0 and
μ = 6.301 mm
-1. 22315
reflections were measured (8.43≤2
θ≤158.10°), of which 3532 were unique (
Rint = 0.0311) and used in all calculations. The final
R = 0.0334 (
I > 2
σ(
I))
and
wR = 0.0842 (reflections). The title
compound showed over 50% of growth inhibition against
Botrytis cinereal,
Cercospora
arachidicola,
Gibberella zeae,
Rhizoctonia solani and
Sclerotinia sclerotiorum at 50 mg/L, and
its EC
50 value against
R. solani was 60.44 µmol/L, which was active at the same level as that
of positive control diflumetorim
with its EC
50 value of 60.29 µmol/L and less active than
YZK-C22 with its EC
50 value
of 12.32 µmol/L, respectively. Our studies discovered that the combination of bioactive substructures
of isothiazole with purine could be an
effective way to novel fungicide development.