Science of Synthesis

Hajos, G.; Riedl, Z., Science of Synthesis, (2002) 12, 618.

In contrast to Section ‌12.5.1.1.1.1‌, where in most cases the first reaction step is the quaternization of a pyridin-2-amine derivative followed by nucleophilic attack of the 2-amino group on an appropriate functional group to form the imidazole ring, several ring closures have been elaborated starting from substituted pyridin-2-amines. In these cases, the β-carbon atom of the carbon chain attached to the 2-amino group bears an appropriate functional group, and a nucleophilic attack of the pyridine ring nitrogen atom at this center results in formation of the imidazole ring. Such syntheses are shown in ‌Scheme 8‌.

‌Meeeee 8‌ Meee Meeeeee Me Meee Meeeeee[8,8-e]eeeeeeee Meeeeeeeeee Meeeeeee eeee M-Meeeeeeeeee Meeeeee-8-eeeeee[‌88‌–‌88‌]

Meeeeeee ee 8-eeeeeeeeeeeeeeeeeeeee (‌88‌) eeee eeeeeeeeeeeeeeeee eeeeeeee eeeeee (‌88‌) eeeeee eee eeeeeeeeeeee ‌88‌, eeeee ee e eeeeeeee eeeeeeee eeeeeeee eee eeee eeeeeee ee eee eeeeeeeeeeee 8-eeeeeeeeeee eeeeeeeeee ‌88‌.[‌88‌] M eeeeeee eeee eeeeeee eeeeeeee eeee eee eeeeeeeeeee eeeeeeeeeeeeeeeee ‌88‌ eeeeeee eee eeeeeeeee eeeeeeee ‌88‌ ee e eeeeeeeeeee eeeeeeeeee (ee 888°M) ee eeeeeeee eeeee.[‌88‌] Me eeeeeeeeeee eeeee-eeee eeeeeeeee ee eeeeeeeee eee e eeeeee ee 8-eeeeeeeeeee eeeeeee[8,8-e]eeeeeeeee eeeeeee: eeeeeeeeeee eeeeeeeeee ee eeeeeee-8-eeeee eeeeeeeeeee ‌88‌ eeeeee eeeeeeeeeeeee ‌88‌, eeeee eeee eeeeeeeee eeee M-eeeeeeeeeeeeeeee eeeeeee eeeeeeeeeee ee ‌88‌. Meeeeeee ee eeeeeee ee eeeee eeeeeeeee eeeee ee eeee eeeeeee ee eeee eeeeeeee eeeeeeeee ‌88‌ ee eeeeeeee ee eeee eeeeee.[‌88‌] M eeeeee eee-eeee eeeeeeee eee eeee eeeeeeeee eee eee eeeeeeeee ee 8-eeeeee eeeeeeeeeee ee eee eeeee eeeeee: eeeeeeee ee ‌88‌ eeee eeeeeee eeeeeeee eeeeeeee ee eeeeeeeee eeee eeeeee eeeeeeeee eeeeeee ‌88‌ ee eeeeeeeeee ee eeeeeeeee eeeeee.[‌88‌] M eeeeeeeeeeeeeee eeeeee eee eeee eeeeeeeeee eee eeeeeeeeeee ee eee eeeeeeeee eeeee eeeeeeeeee ‌88‌: eeeeeeeee ee eeeeeeee-8-eeeee (‌88‌) eeee eeeeeeeeeeee, eeeeee eeeeeeeee, eee eeeeeeeee eeeeeee eeeee eeeeeee[8,8-e]eeeeeeee-8-eeeee (‌88‌) ee 88% eeeee.[‌88‌] Mee eeeeeee eeeeeee[8,8-e]eeeeeeeeeee-8-eeeee (‌88‌) ee eeeeeeee eeee eeeeeeeeeee-8-eeeee (‌88‌) ee eee eeee eeeeeeeee ee eeeeeeee (88%) eeeee. Meeeeeee ee 8-eeeeeeeeeeeee-8-eeeee (‌88‌) eeee eeeeeee (‌88‌) eeeeee eeeeeeeeeeee eeeeeee ‌88‌ ee 88% eeeee, eeeee eeeeeeeee eeee eeeeeee ee eee 8-eeeeee-8,8-eeeeeeee-eeeeeeeeeee eeeeeeeeee ‌88‌ eeee eeeeeee eeee eeeeeeeeeeeeee eeee.[‌88‌]

References