SU75854A1 - Method for producing orthophenanthroline - Google Patents

Description

The disadvantages of the existing methods of producing orthophenanthroline are low yields (25-50%) and the completion of the reaction to the appearance of a strong foaming of the reaction mixture. It has been established that strong foaming, occurring 1.5 to 2 hours after the start of the reaction to produce orthophenanthroline and impeding further observation of the progress of the reaction, is not the end of the reaction.

According to the invention, a method for producing and isolating orthophenanthroline is proposed, the novelty of which is that in order to eliminate foaming and increase the yields, the condensation reaction is carried out in the presence of a small amount of octyl alcohol or other foaming agent.

Ortofenanthr | olin is isolated by extracting the reaction mixture with chloroform, followed by decomposing the obtained complex compound (Ci2H8N2-CtiCls) with water and further purification of phenanthroline by known methods.

The essence of the method is as follows.

In a vessel equipped with a stirrer and refluxing: ohm, 108 g of orthophenylene diamine, 560 g of technical glycerin are mixed,

6 Code Release 6. 1949

540 cm of an 80% aqueous solution of mouse acid and 2.2-2.4 liters of 67-70% sulfuric acid and the reaction mixture is heated to boiling for one hour.

When the reaction mixture is kept at a moderate boiling point, usually after 1 hour, strong foaming begins: the foam fills the entire flask and prevents further reaction. To eliminate foaming through the reflux condenser, a few milliliters of octyl alcohol or another foaming agent are added, causing the foaming to stop and allowing the reaction to continue. As required during the next 5-6 hours. the addition of octyl alcohol is further 2-3 times. After the end of the exposure, usually on another day, the reaction mixture is diluted with an equal volume of water, alkalinized with 20% sodium hydroxide solution to a strongly alkaline reaction, and the precipitated orthophenanthroline mixed with the reaction mixture of gly.

500-600 parts of the product, dried in air, extracted with chloroform in the ratio I: 8, after which chlorof p8t

Variable stretching is evaporated to Vio of the original volume. When cooled from the mother liquor, a double compound of ortofenanthrodin with chloroform (Ci2H8N2 SSCC) in an amount of 160-175 e is crystallized from the mother liquor:

The resulting 160-175 g of double compound is loaded into a flask with distilled water (7.5 L) heated to 70-80 °. After the double compound is dissolved, activated carbon is added to the solution, the solution is boiled for 10-15 minutes. and the chloroform separated off with distilled steam.

The aqueous solution is filtered off from the coal and cooled, after which orthophenanthroline monohydrate crystallizes from the solution with a melting point of 101-102 °. Found 54-57% of

move g theory.

Subject invention

1. A method of producing orthophenanthroline from orthophenylenediamine and glycerol by the Skraup reaction, characterized in that the condensation process, in order to eliminate foaming and increase yields, is carried out in the presence of a small amount of octyl alcohol or other foam that is suspended;

2. Acceptance of the method for and. I, characterized in that, in order to isolate ortofepantroline, the reaction mixture is extracted with chloroform and the Ci2H8N2 CHCls compound released on cooling the chloroform mother liquor is decomposed with water, after which the precipitated orthophenanthroline is purified in a known manner.