Organic compounds -- part of the class 532-570 series – Organic compounds – Amino nitrogen containing
Patent
1989-02-17
1989-10-17
Raymond, Richard L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Amino nitrogen containing
564112, 564414, 564441, C07C 8526, C07C11100, C07C 8511, C07C 8760
Patent
active
048748951
ABSTRACT:
The level of the nitrosamines which may be present in the unrefined trifluralin is reduced to a value below 0.5 ppm, by treating the unrefined trifluralin under agitation, at a temperature from 60.degree. to 90.degree. C., for a time between 10 minutes and 4 hours, with an aqueous solution containing from 15 to 50% by weight of hydrobromic acid in a ratio of 0.2 to 0.8 liters per kilogram of unrefined trifluralin, said aqueous solution of hydrobromic acid being added with an amount of sulfamic acid from 0.1 to 3 g per liter of solution and with an amount of bisulfite or an alkali metal corresponding to a content of sulphur dioxide from 0.3 to 1.2 g per liter of said hydrobromic acid aqueous solution.
The so obtained refined trifluralin has a content of nitrosamines which is lower than 0.1 ppm.
REFERENCES:
patent: 3317607 (1967-05-01), Latourette et al.
patent: 3586719 (1971-06-01), Bil
patent: 3927127 (1975-12-01), Damiano
patent: 4120905 (1978-10-01), Cannon et al.
patent: 4127610 (1978-11-01), Eizember
patent: 4134917 (1979-01-01), Ross et al.
patent: 4136117 (1979-01-01), Diehl et al.
patent: 4185035 (1980-01-01), Eizember et al.
patent: 4226789 (1980-10-01), Eizember et al.
patent: 4338473 (1982-07-01), Habig et al.
patent: 4440962 (1984-04-01), Palluca
patent: 4501608 (1985-02-01), Cannon
patent: 4537992 (1985-08-01), Pikarski et al.
Overberger, et al., Organic Compounds with Nitrogen-Nitrogen Bonds, (1966), pp. 83-98.
Wallis, "Preparation of Pure Piperidine", Lieb. Ann., 345:277 (1906).
Biggs, et al., "Kinetics and Mechanism of the Fischer-Hepps Rearrangement and Denitrosation. Part V. The Mechanism of Denitrosation", J. Chem. Soc. Perkins II, p. 107, (1975).
Fridman, et al., "Advances in the Chemistry of Aliphatic N-Nitrosamines", Russian Chemical Review, 40(1):34-50 (1971).
Eisenbrand, et al., Arneimittel-Forschung, 20(10):1513-1517.
Helvetica Chimica Acta, 47:166 (1964).
Probst, "Reduction of Nitrosamine Impurities in Pesticide Formulations", 181.sup.st Meeting of ACS, Mar. 31-Apr. 1, 1981, pp. 363-382.
Johnson et al., "The Specificity of the Release of Nitrite from N-Nitrosamines by Hydrobromic Acid", Analytical Letters, 4(6):383-386 (1971).
Eizember, R. F. et al., "Destruction of Nitrosamines. Treatment of Nitrosamines with Various Acids and Halogens", J. Org. Chem., vol. 44, No. 5, pp. 784-786 (1979).
Finchimica S.p.A.
O'Sullivan Peter G.
Raymond Richard L.
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