Five grams of the monoamino compound were dissolved in 200 cc. absolute alcohol with the addition of 3 cc. of benzaldehyde and the clear solution was boiled on a water-bath, with a return condenser, for two hours. After the solution was boneblacked, the yellow precipitate was recrystallized from carbon disulphide. The yield was 90 per cent.
It crystallizes in yellow plates, melting at 156.7°-157.6°C., soluble in benzene, ether, ethyl alcohol, carbontetrachloride, acetone, but difficultly soluble in ligroin. An analysis of the crystals showed the following result,
| Calculated for C20H14N2Se | Found | ||
|---|---|---|---|
| Nitrogen | 7.75% | 7.92% | 7.68% |
An Azo Dye
Five and four tenth grams of the monoamino compound were dissolved in hot conc. HCl, cooled in ice, and diazotized with sodium nitrite solution, until starch iodide paper showed excess nitrous acid. The diazotization was performed in ice, with mechanical stirring, and required about an hour. The diazo solution was poured into a solution of 3 grams B-naphthol in 8 grams of NaOH and 60 cc. of water, while gradually stirring. A very deep red solution formed. This was acidified with excess HCl, salted out by NaCl, and crystallized from aniline-alcohol mixture. In the pure state, it is a deep red powder, with a metallic lustre when rubbed, melting at 284.2°C. An analysis showed the following result,
| Calculated for C23H15N3OSe | Found | |
|---|---|---|
| Nitrogen | 9.81% | 9.75% |
Dinitro Derivative
The nitration for the production of dinitro derivative was at first carried out under the same conditions as in the preparation of mononitro compound and after the latter was formed more nitric acid mixture was added with the addition of heat: conc. sulphuric acid, keeping it below room temperature. It was then cooled in a freezing mixture and half the volume of a nitric acid mixture (prepared and cooled by mixing 19 grams of nitric and 30 grams of sulphuric acids) was introduced very slowly to the selenazole solution through a dropping funnel, maintaining at this temperature for two hours (using mechanical stirring). The remaining half of the nitric acid mixture was then slowly introduced and the flask was heated on a water-bath for two hours. The solution was poured into two liters of water, the precipitate filtered off, dried and recrystallized several times from acetic acid. The yield was 80 per cent.
This dinitro compound crystallizes in fine yellow needles, m. p., 246.8°C. (corr.), very insoluble in water, but soluble in hot acetic acid, acetic anhydride, nitrobenzene, nitrotoluene, ethyl alcohol, and difficultly soluble cold. It was analyzed and the following results were found,
| Calculated for C13H7N3O4Se | Found | ||
|---|---|---|---|
| I | II | ||
| Nitrogen | 12.07% | 12.30% | 12.12% |