2-arylthio-4- oxazolones

The nature of the arylthio substituent at C-4 of a 5(277)-oxazolone dictates which of two different synthetic strategies can be used. The first involves the use of sodium cyanodithioformate and the corresponding ketone as starting materials. The reaction occurs through a thiazolone 45 that must be alkylated on the sulfur atom followed by treatment with Hg(OAc)2 to afford the corresponding 4-(alkylthio)-5(2//)-oxazolone 47. The second strategy involves the addition of thiophenol to... 

The thermolysis of 4-(alkylthio or arylthio)-5(277)-oxazolones 57 in the presence of dipolarophiles with activated double bonds leads to hve-membered cycloadducts. 

Reaction of methyl 3-(dimethylamino)-2-isocyanoacrylate (Ri = Me) with acyl chlorides gave 2-acyl-4-(dimethylaminomethylene)-5(477)-oxazolones 375. ° The same reaction with arenesulfenyl chlorides gave either 2-arylthio-4-(dimethylami-nomethylene)-5(477)-oxazolones 376 or an unsaturated 5(477)-oxazolone 377 containing an imidazole at C-2 depending on the substitution present in the arenesulfenyl chloride. Nitroarenesulfenyl chlorides favored 376. ° ° Selected examples of 372, 375, and 376 are shown in Table 7.33 (Fig. 7.44 Scheme 7.121). 

TABLE 7.6 SYNTHESIS OF 4-(ARYLTHIO)-5(2H)-OXAZOLONES FROM ETHYLCYANOFOR-MATE, KETONES AND ARYLTHIOLS, 141... 

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See also in sourсe #XX -- [ , ]

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