Chemistry Reference
In-Depth Information
NC
CN
N
O
Br
2
C
5
H
5
N
2
+
N
O
NC
CN
Figure 2.10. Synthesis of TCNQ.
NH
4
Cl
Zn/H
2
O
MeOH
NaOH
I
2
/H
2
O
EtOH
NO
2
NHOH
(a)
NO
2
NO
2
NHOH
OH
O
N
N
NHOH
(b)
+
R-CHO
R
R
NHOH
N
N
OH
O
Figure 2.11. Scheme of the synthesis of
α
-nitronyl nitroxides.
films will be studied in Chapters 5 and 6, respectively. The synthesis route, shown
in Fig. 2.11, can be divided into two steps (Osiecki & Ullman, 1968). The first is
the synthesis of 2,3-dimethyl-2,3-bis(hydroxylamino)-butane from 2-nitropropane
through dimerization of 2-nitropropane (Fig. 2.11(a)), followed by the reaction
of the 2,3-dimethyl-2,3-bis(hydroxylamino)-butane species with aldehydes with
sodium periodate or lead dioxide giving the nitronyl nitroxide (Fig. 2.11(b))
p
-
NPNN corresponds to the case R
nitrophenyl.
The synthetic pigment CuPc was obtained by serendipity in 1927 but not iden-
tified as such by the authors probably due to analytical limitations and/or because
attention was focused on other compounds (de Diesbach & von der Weid, 1927).
Upon reaction of
o
-C
6
H
4
Br
2
with cuprous cyanide and C
5
H
5
N a blue insoluble
compound was obtained, which undoubtedly was CuPc. Basically there are two
commercially important processes to produce CuPc. One is based on phthaloni-
trile and the other one uses phthalic anhydride. The phthalonitrile process often
yields a product with fewer impurities and using metallic copper gives CuPc by
cyclotetramerization.
=
