Rigid bolaamphiphiles with lateral alkyl chains such as 1 form columnar mesophases of a novel type based on microsegregation of the three incompatible parts of the molecules (shown schematically).
The reaction of 3-nitropyridine with an aqueous solution of sodium sulfite gave the disodium salt of 5-(N-sulfohydroxyamino)pyridine-2-sulfonic acid (2) which on treatment with an acidic ion exchange resin gave 5-hydroxyaminopyridine-2-sulfonic acid (3). The yield of 3 from 3-nitropyridine was 63%. The structures of the products were verified by X-ray analysis.
3-Nitropyridine and 4-substituted-3-nitropyridines were reacted with chloroform, methyl chloroacetate and ethyl 2-chloropropionate under vicarious nucleophilic substitution (VNS) conditions. Substitution was obtained in the ortho or para position to the nitro group with acceptable to good yields and regioselectivity. With potassium 5-nitropyridine-2-sulfonate the substitution took place in the 4-position. Further substitution of the sulfonate group proved to be possible.
We have investigated reactions of 5-nitropyridine-2-sulfonic acid and its potassium salt in which substitution of the sulfonate group by oxygen, nitrogen and halogen nucleophiles has been attempted. By this approach, 2-methoxy- (95% yield), 2-ethoxy- (97%), 2-isopropoxy- (65%), 2-amino- (92%), 2-butylamino- (76%), 2-diethylamino- (62%), 2-ethylamino- (32%), 2-benzylamino- (77%), 2-(R-1-phenylethylamino)- (71%) and 2-chloro-5-nitropyridine (87%) have been obtained. No reactions were observed with phenols or anilines. With t-BuOH, 2-hydroxy-5-nitropyridine was formed together with 2-methylpropene.
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