Interaction of O,O-Dialkyl Chlorothiophosphates with Oximes of Hydrolysis Lignin and Its Derivatives
Abstract Generated abstract
This paper investigates the conversion of hydrolysis lignin and chlorinated, nitrated, and chloronitrated derivatives into oximes and their subsequent reaction with O,O-dialkyl chlorothiophosphates. Oximes were prepared from carbonyl-containing lignin materials, transformed into potassium salts, and esterified in organic solvents or aqueous media to give phosphorus-containing O-iminothiophosphate products, which were characterized mainly by nitrogen and sulfur analyses. The synthesized compounds showed contact insecticidal activity against houseflies, with several preparations producing complete mortality under the reported test conditions, and selected products also exhibited acaricidal activity against ixodid ticks.
Full Text
REACTION OF O,O-DIALKYL CHLOROTHIOPHOSPHATES WITH HYDROLYSIS LIGNIN OXIMES AND ITS DERIVATIVES
A. I. Galochkin, L. A. Pershina
(Presented by the scientific seminar of the Faculty of Chemical Technology)
In the esterification of the hydroxyl groups of hydrolysis lignin and its chloro- and nitro derivatives with O,O-diethyl chlorothiophosphate, compounds are obtained that possess fairly strong insecticidal properties [1]. The number of hydroxyl groups can be increased by preparing lignin oximes from carbonyl groups.
The hydroxyl groups of oximes are capable of forming stable simple and complex esters [2, 5]. Prince, Glenn R. et al. [4] patented a method for obtaining thiophosphates of certain cyclic ketoximes, active as insecticides, acaricides, and fungicides.
We have obtained oximes of lignins: hydrolysis lignin treated with sulfuric acid, hydrochloric acid, chlorinated lignin, and lignin oxidized with nitric acid. From the potassium salts of the above-listed lignin oximes and O,O-dialkyl chlorothiophosphate, phosphorus-containing compounds of the O-iminyl thiophosphate type were synthesized; these exhibited a stronger insecticidal action than the corresponding thiophosphates.
Experimental Part
1. Preparation of chlorolignin
50 g of hydrolysis lignin, previously dried to an air-dry state, ground in a ball mill, and sieved through a sieve with an aperture diameter of 0.25 mm, was placed in a three-necked flask equipped with a mechanical stirrer and a bubbler. Into the flask were poured 750 ml of water, and for 4 or 8 hours at a temperature of 20–25°C gaseous chlorine was passed through the bubbler into the flask.
The product obtained was filtered off and washed with distilled water until a negative reaction for the Cl⁻ ion was obtained.
Depending on the time for which chlorine was passed through the reaction mass, different amounts of chlorine entered the lignin. For our investigations we used chlorolignins with chlorine contents of 27.4% (chlorination time—8 hours) and 8.4% (chlorination time 4 hours).
2. Preparation of nitrolignin
50 g of lignin was placed in a flask with 700 ml of 12% nitric acid. The reaction mass was kept at a temperature of 50–52°C for a period of
8 hours, after which the product obtained was washed with water until a negative reaction for the \(\mathrm{NO_3^-}\) ion was obtained (with \(\alpha\)-naphthylamine).
3. Preparation of chloro-nitro-lignin
20 g of nitrolignin, obtained under the conditions described earlier, was placed in a three-necked flask equipped with a mechanical stirrer and a bubbler. 300 ml of water was added to the flask, and for 4 hours at a temperature of 20–25°C gaseous chlorine was passed through the bubbler into the flask. The product obtained was filtered off, washed with distilled water until a negative reaction for the \(\mathrm{Cl^-}\) ion was obtained, dried, and analyzed.
Analytical data for hydrochloric-acid lignin, sulfuric-acid lignin, and its chloro-, nitro-, and chloro-nitro derivatives are presented in Table 1.
4. Preparation of oximes
To a weighed portion of lignin suspended in ethanol, hydrochloric-acid hydroxylamine was added in a twofold excess relative to the calculated amount based on the carbonyl-group content. After the reaction mixture had been heated at its boiling temperature for 1 hour, an alcoholic solution of potassium hydroxide was added in small portions to pH 7.5–8.0. The reaction mixture was kept for another hour, acidified with a dilute solution of hydrochloric acid to pH \(\pm 6\), and poured into a large amount of cold water. The precipitate was washed several times with a dilute solution of hydrochloric acid to remove excess hydroxylamine, then with distilled water until a negative reaction for the \(\mathrm{Cl^-}\) ion was obtained. Table 1 gives analytical data for the oximes obtained.
5. Preparation of O-iminothiophosphates of hydrolysis lignin and its derivatives
The synthesis of O-iminothiophosphates was carried out by two methods: in toluene or benzene and in an aqueous medium.
Table 1
| No. | Lignin | Initial product: N, % | Initial product: Cl, % | Initial product: OH, % | Initial product: \( \mathrm{C(=O)H} \), by Bertrand, % | Initial product: \( \mathrm{C(=O)H} \), by hydroxylamine, % | Reaction product: N, % |
|---|---|---|---|---|---|---|---|
| 1 | Hydrochloric-acid | — | — | 8.5 | 2.5 | 2.5 | 1.4 |
| 2 | Sulfuric-acid | — | — | 5.2 | 2.1 | 2.9 | 1.4 |
| 3 | Nitrolignin, sulfuric-acid | 3.0 | — | 6.9 | 4.5 | 2.4 | 4.5 |
| 4 | Chlorolignin, sulfuric-acid | — | 27.4 | 5.3 | — | 4.1 | 2.0 |
| 5 | Chlorolignin, sulfuric-acid | — | 8.4 | 5.9 | — | 6.0 | 3.2 |
| 6 | Chloronitrolignin, sulfuric-acid | 3.6 | 4.5 | 6.1 | — | [[unclear: value begins with “6,”]] | 3.8 |
Table 2
| No. | Oximes | Oxime or its salt | Toluene | Water | Diethyl chlorothiophosphate | N, % | S, % | Preparation No. when activity was tested | Contact time | Mortality of flies by day 1, % | Mortality of flies by day 2, % | Mortality of flies by day 3, % |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Hydrochloric acid lignin | 5 | — | 100 | 4.65 | — | 2.0 | 20 | 24 h | 100 | 2 | — |
| 2 | Sulfuric acid lignin | 5 | 100 | — | 5.0 | 4.59 | 2.7 | 24 | 24 h | 80 | 100 | — |
| 3 | ” | 10 | — | 100 | 7.0 | 4.60 | 1.4 | 14 | 24 h | 0 | 0 | 0 |
| 4 | Chlorolignin | 5 | 100 | — | 7.7 | — | — | 21 | 24 h | 100 | — | — |
| 5 | ” | 5 | — | 100 | 7.7 | 3.30 | — | 17 | 24 h | 100 | — | — |
| 6 | Chlorolignin ($C = 8.4\%$) | 10 | 200 | — | 15.5 | — | 4.0 | 30 | 35 min | 100 | — | — |
| 7 | Nitrolignin | 10 | — | 100 | 14.0 | 2.4 | 8.2 | 25 | 10 min | 100 | — | — |
| 8 | ” | 10 | 100 | — | 7.7 | 4.4 | — | 22 | 2 h | 100 | — | — |
| 9 | Chloronitrolignin | 3.7 | — | 50 | 3.6 | 4.2 | 4.2 | 7 | 24 h | 100 | — | — |
*) In benzene medium and in the presence of triethylamine.
The dry potassium salt of the oxime was placed in a round-bottom flask equipped with a reflux condenser, a dropping funnel, and a stirrer; toluene and 2–3 drops of pyridine were added. At a temperature of 115°C, the calculated amount of $O,O$-diethyl chlorothiophosphate was added dropwise. The reaction mixture was heated for 2 hours. The precipitate was filtered off and washed until the wash waters gave a negative reaction for the $Cl^-$ ion.
In the case of chlorolignin containing 8.4% chlorine, the reaction was carried out under the following conditions.
Into a reaction flask equipped with a stirrer with a hydraulic seal, a dropping funnel, a reflux condenser, and a gas-inlet tube were placed 10 g of lignin oxime and 200 ml of benzene. With continuous stirring, 8 g of $O$-methyl–$O$-ethyl chlorothiophosphate was added dropwise to the contents of the flask over 30 minutes. Simultaneously with the addition of the latter, trimethylamine was passed into the reaction flask through the gas-inlet tube. The contents of the flask were heated at 80°C for 1.5 hours with continuous stirring. The product obtained was washed with benzene, dried, and, in order to remove the trimethylamine hydrochloride, treated with a large amount of water.
According to the second method for obtaining $O$-iminothiophosphates, lignin oximes were placed in a flask, to which the calculated amount of alkali and $O,O$-diethyl chlorothiophosphate was added. At a temperature of 95–97°C, the reaction mixture was heated for two hours. The precipitate was filtered off and washed until a negative reaction for $Cl^-$ and $PO_4^{---}$ was obtained.
In the $O$-iminothiophosphates obtained, nitrogen was determined by the Kjeldahl method, and sulfur by the hydrogenation method. The amounts of starting substances and the analytical data are presented in Table 2.
The $O$-iminothiophosphates synthesized from hydrolysis lignin and its derivatives were tested on houseflies as contact insecticides. Preparations Nos. 20, 21, and 22 possess acaricidal activity when tested on ixodid ticks (Ixodes persulcatus).
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