US EPA

1627518 

Journal Article 

Photochemical desulfurization of methylthio-s-triazines 

Plimmer, JR; Kearney, PC; Klingebiel, UI 

1969 

1 

Tetrahedron Letters
ISSN: 0040-4039
EISSN: 1873-3581 

HAPAB/70/01767 

No 

REF:6 

3891-2 

HAPAB The photolysis of the 2-methylthio-s-triazines was investigated to determine whether the conversion sequence methylthio-bis ( alkylamino ) -s-triazine herbicide ( I ) to 2-hydroxy-bis ( alkylamino-s-triazine ) via the intermediate sulfoxide ( II ) and sulfone ( II ) could also accur by photooxidation. Solid 2-methylthio-4,6-bis ( ethylamino ) -s- triazine ( simetryne ) was irradiated in air with a sun lamp ( output maximum 310 nm ) for a period of 72 hr. The products were assayed by thin-layer chromatography ( TLC ) on silica. A 2:1 benzene-acetone solution was used as a solvent. Only one compound was detected in addition to the starting material and was identified as 2,4-bis ( ethylamino ) -s-triazine. The identity was confirmed by mass spectrometric analysis. Similar results were obtained when 2- methylthio-4,5-bis ( isopropyl amino ) -s-triazine ( prometryne ) was irradiated. TLC analysis of the single photoprouct showed that II and III were absent. The mass spectral fragmentation pattern indicted that the product was 2,4-bis ( isopropylamino ) -s-triazine. The nature of the sulfur-containing compound which evolved on photolysis is unknown. Evaluation of the data led to the belief that photoxidation of the methylthio-group to a sulfoxide or sulfone before elimination of a sulfur-containing fragment would afford a 2-hydroxy-s-triazine. A study is being made of the photochemistry of II and III. TOXICOLOGY AND PHARMACOLOGY 70/10/00, 483 1969