5.6- Diamino-3-methylthio triazines

Photolytlc. The dye-sensitized photodecomposition of ametryn was studied in aqueous, aerated solutions (Rejto et al, 1983). When an aqueous ametryn solution was irradiated in sunlight for several hours, 2-(methylthio)-4-(isopropylamino)-6-amino-5-triazine and 2-(methylthio)-4-(iso-propylamino)-6-acetamido-5-triazine formed in yields of 55 and 2.6%, respectively. Continued irradiation of the solution led to the formation of 2-(methylthio)-4,6-diamino-5-triazine which eventually decomposed to unidentified products (Rejto et al., 1983). The UV (7, = 253.7 nm) photolysis of ametryn in water, methanol, ethanol, n-butanol, and benzene yielded the 2-//analog 4-(ethylamino)-6-isopropylamino-5-triazine. Photodegradation was not observed at wavelengths >300 nm (Pape and Zabik, 1970). 

Among heterocyclic compounds, S-triazines are of great environmental concern, as different compoimds, largely used, derive from their nucleus. All S-triazines, used as herbicides, are diamino-S-triazines bearing a chloro, methoxy or methylthio group, linked directly to the nucleus. Among these compounds, atrazine (2-chloro-4-ethylamino-6-isopropyl-... 

Diamino-3-methylsulfinyl-l,2,4-triazme 1-oxides 166 were synthesized using the same procedure starting from 5,6-diamino-3-methylthio-l,2,4-triazines 167 [96JCS(P1)2253]. 

Diamino-3-methylthio-l,2,4-triazine 78 reacts with phenacyl bromide to give the enamine 79 and no cyclic product. However, the cyclisation is successful with bromoacetone to give the pyrazinotriazine 80. The cyclisation is also successful using 5,6-diaminotriazin-2(lH)-one <96H(43)1007>. 

Methiotriazamine, l,6-Dihydro.6.6.dimethyl-I-[4-(methylthio pkenytJ-l,3tS-triazine-2,4-diamine 4.6-di-amino-I,2-dihydrO-2,2-dimetbyl l-[p-[Pg.943]

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