SYNTHESIS OF A NAPHTHOTETRAZINE FROM DIE- 
THYL SUC CINYLO SUCCINATE AND 
DICYANDIAMIDE . 
ARTHUR W. DOX. 
On account of the ease with which dicyandiamide can he pre- 
pared in quantity and at very small cost from the crude calcium 
cyanamide of commerce, this substance is beginning to find numer- 
ous applications in organic syntheses. Among other properties, 
the amidine structure of dicyandiamide has been taken advan- 
tage of for the preparation of certain nitrogen heterocycles. For 
example, by condensation with such substances as a -ketone acid 
esters, various pyrimidine derivatives are obtained. Thus, dicy- 
andiamide condenses with amlonic ester derivatives 1 and with 
acetoacetic 2 ester to form substituted pyrimidines. It is not im- 
probable that dicyandiamide is capable of entering into the 
same condensation reactions and yielding cyanamino derivatives 
or ihe various heterocycles now prepared from guanidine. 
The readiness with which dicyandiamide yields pyrimidine 
derivatives suggested to the writer the possibility of preparing 
til, 8, 6, 8 — naphthotetrazine, or symmetrical benzodipyrimidine, 
by condensation with succinylosucciuic ester. Other amiclines 
have been condensed with succinylosuccinic ester, forming sub- 
stituted naphthotetrazines. Thus, benzamidine 3 yielded 2, 7 — 
diphenyl — 4, 9 — diketotetrahydro — 1, 3, 6, 8 — naphthotetrazine, 
guanidine 4 the corresponding 2-7 — diamino, and acetamidine 5 the 
corresponding 2-7 — dimethyl derivatives. Other derivatives of 
this heterocycle have been prepared by Bogert and Nelson 6 from 
p — diaminoterephthalic acid and its derivatives. They all appear 
to be characterized by insolubility, infusibility and general in- 
ertness. 
German Patent 165, 223, 1905. 
2 Soll & Stutzer, Ber. 42, 4534, 1910. 
3 Pinner, E'er. 22, 2609, 1889. 
4 Bogert and Dox. J. Amer. Chem. Soe., 27, 1127, 1905. 
5 Bogert & Dox, ibid., 27, 1136, 1905. 
6 Bogert & Nelson, ibid., 29, 729. 1907. 
