Sulfuric Acid → HCID 13567771, compound
Reaction equation
[H-].C([Al+]CC(C)C)C(C)C.CS([C:15]1[CH:20]=[CH:19][C:18]([S:21]([CH3:24])(=[O:23])=[O:22])=[CH:17][N:16]=1)(=O)=O.S(=O)(=O)(O)[OH:26].[I-:30].[K+].I([O-])(=O)=O.[K+]>>[I:30][C:20]1[C:15](=[O:26])[NH:16][CH:17]=[C:18]([S:21]([CH3:24])(=[O:23])=[O:22])[CH:19]=1Participants
5
Procedure
In what could be considered as a variation of scheme III, a Heck reaction could be carried out using ethenyl alcohol V and 2-chloro-3-iodo-5-(methylsulfonyl)pyridine to give a ketone analogous to VI except that the methoxy group is replaced by a 2-chloro. This ketone would then be reduced to the corresponding alcohol using diisobutylaluminum hydride at low temperature and the resulting alcohol would be cyclized as described earlier for 2-chloropyridines. The necessary iodo compound used in this procedure can be obtained by starting with 2,5-bis(methylsulfonyl)pyridine and treating it with sulfuric acid to hydrolyze the 2-substituent followed by iodination with potassium iodide/potassium iodate with the procedure giving 3-iodo-5-(methylsulfonyl)-2(1H)-pyridinone as the product. This is then treated with phosphorus oxychloride to give the corresponding 2-chloropyridine. The corresponding compound containing bromide in place of iodine can be obtained by using a brominating agent instead of an iodinating agent in the procedure described above followed by conversion to the 2-chloro compound. The resulting 3-bromo compound could be used in the same way as the 3-iodo compound.