ALTERNATIVE FORMATION OF PRODUCTS OF DIRECT OR CINE METHOXYDENITRATION OF 1-ALKYL-3,4-DINITROPYRROLES

l-Alkyl-3, 4-dinitropyrroles 1 with methoxide ion in refluxing methanol yield irons-1-alkyl-4, 3-dimethoxy-3-nitro-2-pyrrolines 2. Theacid-promoted elimination of methanol from 2 is regioselective, yielding 1-alkyl-2-methoxy-4-nitropyrroles 3, whereas the base-promoted elimination, under heterogeneous conditions, yields regiospecifically l-alkyl-3-methoxy-4-nitropyrroles 5. Acid-promoted reactions in ethanol or CD3OD indicate the fast exchange of one alkoxy group of pyrrolines 2, probably as a consequence of the ready formation of a cationicadduct. © 1979, American Chemical Society. All rights reserved.