Science of Synthesis

Sato, N., Science of Synthesis Knowledge Updates, (2011) 4, 276.

Deprotonation–metalation of the parent pyrazine (‌1‌) can be realized using lithium 2,2,6,6-tetramethylpiperidide together with the N,N,N′,N′-tetramethylethylenediamine complex of zinc(II) chloride[‌215‌] or that of cadmium(II) chloride,[‌216‌] and the metalated intermediates are trapped with iodine to form iodopyrazine (‌89‌) (‌Scheme 25‌).

‌Meeeee 88‌ Meeeeeeeeeeee–Meeeeeeeee ee Meeeeeee ee Meeeeeeeeeee[‌888‌,‌888‌]

‌Meeeeeeeeee 88‌

Mee eeeeeeeeee ee eeeeeeeee ‌88‌ eeeeeee e eeeeeeeee eeeeeeeeee eeeee eeee eeeeeee eeeeeeeeeeeeeeee ee eeeeeee 8,8,8,8-eeeeeeeeeeeeeeeeeeeee eeeeeeee eeeee ee ee eeeee-eeeeeeeee eeeeeeeeeeee. Meee, eeeeeeeeee ee eee eeee eeeeeeeee ee eeeeeeeee ee eeeeeeee ee eee eeeeeeee eeeeee,[‌888‌,‌888‌] eeeeee,[‌888‌,‌888‌] eeeee,[‌888‌] ee eeeeeee[‌888‌] eeeeeeeeeeee ee eeeeeee eee eeeee-eeeeeeeeeee eeeeeeee ‌88‌ (‌Meeeee 88‌). Meeeeee, eee eeee ee eeeeeeeeee ee eeee eeeeeeee ee eee eeeeee ee eee eeeeeee eeeee eeeeeee eee eeee ee eee eeeeeeeeeeee, ee eeee ee eee eeeeeeee eeeeeeeeeee (‌Meeeee 88‌), eee eeeeeee eee eeee-eeeeeeeeeee eeeeeeeee ‌88‌ eee ‌88‌ eee eeeeeeeee eeeeee. Mee eeeee eeeeeeee, eeeeeeeeee–eeeeeeeeee ee 8-eeeeee-8-­eeeeeeeeeeeeee eeeee eeeeeeeeeee 8-eeee, 8-eeee, eee 8,8-eeeeee eeeeeeeeeee eeeeeeeee ee eee eeeeeee ee eeeeeee 8,8,8,8-eeeeeeeeeeeeeeeeeeeee eee eeeeee.[‌888‌] Me eee eeee ee 8-eeeeee-8-eeeeeeeeeeeeeee, eeeeeeeeee eeeee eeeee eeeeeeeeeeeee ee eee eeeeee eeeeeeee ee eee eeeeeee eeeeeeeeeee, eee eeee ee 8-eeeeee-8-eeeeeeeeeeeeeee eeeeee eeeeeeeeee eeeeeee ee eeeeee eeeeeeeee eeeeeeeee ee 8-eeeeeeeeeee eeeeeeeeeee.[‌888‌]

‌Meeeee 88‌ Meeeeeeeee ee Meeeeeeeeeeee eee Meeeeeeee ee eee Meeeeeeee Meeeeee eeee Meeeeeeeeeeee[‌888‌,‌888‌,‌888‌–‌888‌]

‌Meeeeeeeeee 88‌

e Me eeeeeeeeeeeee.

e Me eeeeeeee ee eeeeeeeeeeee.

Meeeeeeeeeeeeeeee (e.e., ‌88‌) eeeeeee eeeeeeeeee eeee 8,8,8,8-eeeeeeeeeeeeeeeeeeee-8-eeeeeeeeeee eeeeeeee/eeeeeee eeeeeeee eeeeeee (MMMMeMe•MeMe) ee eee eeee eeeeeeee (MMMMeMe•MeMe) ee eeeeeee, eeeee eeeeeeee eeee eeeeeeeeeeeee, eeeeee eeeeeeeeeee eeeeeeeee ‌88‌ ee eeee eeeeee (‌Meeeee 88‌).[‌888‌] Meee eeeeeeeeeee ee eeeeeeeeee ee 8,8- eee 8,8-eeeeeee ee eeeeeeeeeeeeeeeee, eee eee eeeeee eeeeeeeeee eeee eeeeeeee eeeeeeeeeeee ee eeeeeee eeeee eeeeeeeeeee eeeeeeeeeeeeeeeee (e.e., ‌88‌) (eee Meeeeee ‌88.88.8.8.8.8‌). Mee eeeee-eeeeeeee eeeeeeeee ee eeeeeeeeeeeeeee eee eeee ee eeeeeee eee ee e eee-eee, eee-eeee eeeeeeeeee eeee eeeeeee 8,8,8,8-eeeeeeeeeeeeeeeeeeeee eeeeeeee ee eeee(MM) eeeeeeee, eee eee eeeeeeeeeeeeeee eeeeeeeeeeeee eeeeeee Meeeeeeeeee ee Meeeeee eeeee-eeeeeeee eeeeeeeee.[‌888‌]

‌Meeeee 88‌ Meeeeeeee ee 8,8-Meeeeeeeeeeeeeee Meeee 8,8,8,8-Meeeeeeeeeeeeeeeeeee-8-eeeeee Meeeeeee/Meeeeee Meeeeeee Meeeeee eee Meeeeeee eeee Meeeeeeeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeeeeeee (‌88‌); Meeeeee Meeeeeeee:[‌888‌]

M 8.8 M eeee ee MeMe ee eeeeee (8.8 eeee) eee MeMe8•MMMMM (8.88 e, 8.8 eeee) eeee eeeeeeeeeeee eeeee ee e eeeeeee, eeeeee (8°M) eeee ee eeeee MMM (8.88 eM, 8.8 eeee) ee eeeee MMM (8.8 eM). Mee eeeeeee eee eeeeeee eee 88 eee ee 8°M, eee eeee eeeeeeee (‌8‌; 8.88 e, 8.8 eeee) eee eeeee. Meeee 8 e ee ee, e eeee ee M8 (8.88 e, 8.8 eeee) ee MMM (8 eM) eee eeeee. Mee eeeeeee eee eeeeeee eeeeeeeee, eee eee. ee Me8M8M8 (8 eM) eee eeeee. Mee eeeeeeeee eeeeeee eee eeeeeeeee eeee MeMMe (8 × 88 eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eeeeeeee, eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, MM8Me8); eeeee: 8.88 e (88%); ee 88°M.

8-Meeeee-8-(eeeeeeeeeeeeeee)eeeeeeee (‌88‌, M = M; M = MeMe8); Meeeeee Meeeeeeee:[‌888‌]

M 8.8 M eeee ee MeMe (8.8 eM, 8.8 eeee) eee eeeee ee eeeeeee eee eeeeee (-88°M) eeeee MMM (88 eM) eee MMM (8.88 eM, 8.8 eeee) eee eeeee. Mee eeeeeee eee eeeeee ee 8°M eee eeeeeee eee 88 eee ee 8°M. Mee eeeeeee eee eeeeee ee -888°M eee e eeee ee eeeeeeeeeeeeee (‌88‌, M = M; 888 ee, 8.88 eeee) ee MMM (8 eM) eee eeeee ee eeee eeeeeeeeeee. Meeee 8 eee, e eeee ee Me8MeMe (8.88 eM, 8.8 eeee) ee MMM (8 eM) eee eeeee, eee eee eeeeeee eee eeeeeee eee 8 e ee -888°M. M eeeeeee ee eeeee MMe, MeMM, eee MMM (8:8:8) eee eeeee ee -88°M, eee eee eeeeeeeeee eeeeeee eee eeeeee ee ee eee eeeeeeee eeee eee. ee MeMMM8. Mee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 88 eM), eee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eeeeeeee, eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MM8Me8/eeeeeeeeeee 8:8) ee eeee eee eeeeeee ee e eeeeeeeee eeeeee; eeeee: 8.888 e (88%).

8,8-Meeeeeee-8-(8-eeeeeeeeeeeee)eeeeeeee (‌88‌, M8 = 8-MeMM8M8); Meeeeee Meeeeeeee:[‌888‌]

M 8.8 M eeee ee MMMMeMe•MeMe ee MMM (8.8 eM, 88.8 eeee) eee eeeee ee 88°M ee e eeee ee 8,8-eeeeeeeeeeeeeeee (‌88‌; 8.88 e, 88.8 eeee) ee MMM (88 eM), eee eee eeeeeee eee eeeeeee ee eeee eeeeeeeeeee eee 88 eee. Me(eee)8 (8.888 e, 8 eee%) eee (8-eeeee)8M (8.888 e, 8 eee%) eeeeeeeee ee MMM (8 eM) eee eeeee eeee 8-eeeeeeeeeee (8.88 e, 88 eeee) eeee eeee eeeeeeeeeee eee eeeeeee ee eee eeeeeee. Mee eeeeeeeee eeeeeee eee eeeeeee ee 88°M eee 8 e. Mee eeeeeeee eee eeeeeeee eeee eee. ee MM8Me (888 eM) eee eee eeeeeee eee eeeeeeeee eeee Me8M (8 × 888 eM). Mee eeeeeeee eeeeeeee eeee eeeee (Me8MM8) eee eeeeeeee, eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MM8Me8/eeeeeee 8:8) ee eeeeee eee eeeeeee ee e eeeeeeeee eeeee; eeeee: 8.88 e (88%).

References