Isothiazoles, nitro-, synthesis

Acetyl- and 5-formylisothiazoles are readily available from 5-lithioisothiazoles.71,102 However, 3-methyl-4-nitroisothiazole does not form a lithium derivative,72 and 4-formyl-3-methyl-4-nitro-isothiazole was prepared by reduction of the appropriate acid chloride with lithium tri-Lbutoxyaluminum hydride.140 A 5-formyl-4-hydroxy-isothiazole has been prepared by direct ring synthesis [Eq. (12)].29... 

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