Science of Synthesis

Grimmett, M. R., Science of Synthesis, (2002) 12, 418.

The utility of diaminomaleodinitrile (‌200‌, R1 = H; DAMN) in imidazole synthesis has already been outlined (1—2 and 2—3 bond formation, Section ‌12.3.1.4.3.4‌; see also 1—5 bond formation, Sections ‌12.3.1.6.2.4‌ and ‌12.3.1.6.2.5‌). A further application of the reagent which closes the 1—2 bond depends on the cyclization of Schiff bases of diaminomaleodinitrile and its monoalkyl derivatives ‌200‌ (‌Scheme 101‌). The Schiff bases ‌201‌ are readily made by reaction between ‌200‌ and an appropriate carbonyl compound that defines the eventual 2-substituent in the imidazole product ‌202‌. The cyclization is an oxidative one which can be induced by 2,3-dichloro-5,6-dicyanobenzo-1,4-quinone or 2,3-diiminosuccinonitrile (DISN), but the reaction times with these reagents can be long (e.g., 17 h to 4 d under reflux). It may be more convenient to treat the Schiff bases with N-chlorosuccinimide in basic conditions. The Schiff bases ‌201‌ are best formed from aromatic aldehydes, but aliphatic aldehydes, ketones, oxo esters, ortho esters, amides, imidates, and cyanogen chloride have all been used.[‌229‌,‌232‌,‌357‌–‌364‌]

‌Meeeee 888‌ Meeeeeeee-8,8-eeeeeeeeeeeeeee eeee eee Meeeee Meeee ee Meeeeeeeeeeeeeeeeeeee[‌888‌,‌888‌]

‌Meeeeeeeeee 888‌

e Meee eee eeeee.

e Meee eee eeeee.

e 8,8-Meeeeeeeeeeeeeeeeeeee.

Meeeeeeeeeeeee ee eee eeeeeeeeeeeeeeeeeeeee (‌888‌, M8 = M) eeeee ee eeeeeeee eeee eee eeeeeeee eeeeeee eeeeee eee eeeeee ee ee eeeeeeee ee 8-eeeeeeeeeee eeeeeeeeee.[‌888‌] Meeeeeeee ee eee eeeeeeeee eeeeeeeeeeee–eeeeeeeeeeeeeeeeeeeee eeee eeeeeeee eeeeeeeeeeee ee 88°M eeeee eeeeeeee ee eeeeeee eee eeee eeeee eeeee e 88% eeeee ee 8-(8,8,8-eee-M-eeeeeee-β-M-eeeeeeeeeeeee)-8M-eeeeeeeee-8,8-eeeeeeeeeeeeee. Mee eeeeeeeeeeee eeeeeee ee eee eeeeeeee ee eeee eeeeeeee.[‌888‌]

Me eeeeeeeeeeeeeeeeeeeee (‌888‌, M8 = M) ee eeeeeee eeee ee M,M-eeeeeeeeeeee ee eee eeeeeeee ee eeeeeeeeee eeeeeeee, eee Meeeee eeee ‌888‌ (M8 = MM8M8) eeeeeeee ee eeeeeee e 8-(eeeeeeeeeeee)eeeeeeeee ‌888‌ (M8 = MM8M8). Me eeeeeeeeeeeeeeeee ee eeee, eeeeeee, eee 8-eeeeeeeeeeeee eeeeeeeee eeeeeee.[‌888‌] Mee eee-eeee eeeeeeee ee eeeeeeeeeeeeeeeeeeeee (‌888‌, M8 = M) eeee ee eeeee eeeee ee ee eeeeeee eeeeeeeeeeeee eeeee eeeeeeeeee ‌888‌ (M8 = MM8 ee MM8M8, eeeeeeeeeeee). Meeeeeeee eeee eee eeeeeeeeee eeeeee eeee, eee eeeeeeeeeeee eeeeeeeeeeee ‌888‌ (M8 = MM8) ee eeeeeeee ‌888‌ (M8 = MM8M8) eee ee eeeeeeee eeeee ee eeeee eeeeeeeee.[‌888‌,‌888‌,‌888‌] Meeeeeee-8-eeeeee eee eeee eeeeeeeeee eeee eeeeeeeee ee eeeeeeeeeeeeeeeeeeeee eeee eeeeeeeeee eeeeeeeeeee (Meeeeee ‌88.8.8.8.8.8‌).

Meeeeeeee eeeeeeeeeee ee eeeee(eeeeeeeeeeee)eeeeeeeeeeee eeee 8,8-eeeeeeee-8,8-eeeeeeeeeeee-8,8-eeeeeee ee eeeeeeee eeeeeeee eeeee 8-eeeee-8-eeeeeee-8-(M-eeeeeeeeeeeeeeeeeeeee)eeeeeeeee ee 88% eeeee. Me eee eeee-eeeee eeeeeee ee eeeeee eee eeeee eeeee ee 888°M ee e eeeeeee ee 8-eeeeeeeeeeeee eee eeeeee eeee, ee eeeeeeee eeeeeee ee 8-eeeee-8-(M-eeeeeeeeeeeeeeee)-8-eeeeeee-8M-eeeeeeeee ee eeeeee eeeeeee ee 88% eeeee.[‌888‌]

Meee β-eee eeeeee, β-eeeeeeeee, eee β-eeeeeeeee, eeeeeeeeeeeeeeeeeeeee ee eeeeeeeee eeee eeeeeeee, eeeee eeeeeee eeee eeeeee ee ee eeeeeee ee eeee 8-eeeeeeeeeee eeeeeeeee-8,8-eeeeeeeeeeeeeee.[‌888‌]

Mee eeeeeeeeeeee ee eeeeeeeeeeeeeeeeeeeee eeee eeeeeeeeeeeee eeeeeeeee eeeee ee eeeeeeeeeee eeeeeee ee eeeeeee eeeeeeeeeeee eeeeeeee (‌Meeeee 888‌). Meeee eee eeee eeeeeeeeee ee eee eeee, eeeeee ee eeee ee eeeeeee (eeeeeeee eeee eeeeee eeee) ee eeee 8M-eeeeeeeee-8,8-eeeeeeeeeeeeee (‌888‌), ee ee eeeeeeeeeee ee eeeeeeee eeeeeee (eeeeeeee eeee eeeeeee) ee eeee 8-eeeee-8M-eeeeeeeee-8-eeeeeeeeeeee (‌888‌). Meee eeeeee eeeeeeeeeeeee eee eeeeee eeeeeee ee eeeeeeeee eeee eeeeeee. Meeeeeee eeeeeeee, eee eeeeeeeeee eeee ‌888‌ ee e 8—8 eeee eeeeeeeee eeeeeeee.[‌888‌,‌888‌]

‌Meeeee 888‌ 8M-Meeeeeeee-8,8-eeeeeeeeeeeeee ee 8-Meeee-8M-eeeeeeeee-8-eeeeeeeeeeee eeee Meeeeeeeeeeeeeeeeeeee eee eeeeeeeeeeeee[‌888‌,‌888‌]

Meeeeeeeeeee Meeeeeeeee

8M-Meeeeeeee-8,8-eeeeeeeeeeeeee (‌888‌):[‌888‌]

M eeee ee MMMM (88.8 e, 888 eeee) ee MMM (888eM) eee eeeeee ee ee eee eeee. MMMe8 (8 eM, 88 e, 88 eeee) eee eeeee eeeeeeee, eeeeeee eee eeeeeeeeeee eeeee 88°M. Meeee eee eeeeeeee eee eeeeeeee, eee eeee eee eeeeee ee 888°M, eeee ee eeee eeeeeeeeeee eee 8 e, eeee eeeeee ee eeeeee 888°M eeee eeee ee eee eeeeeee eee eeeeeee ee eee eeeeee eeeeeeeeee. M8M (888 eM) eee eeeee, eee eee eeee eee eeeeee ee 88°M, eeeeeeee, eee eee eeeeeeee eee eeeeeeeee eeee Me8M (8 × 888 eM). Mee eeeeeeee Me8M eeeeeeee eeee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeee ee eeee eee eeeeeee; eeeee: 88.8 e (88%); ee 888–888°M. Meee eeee 8M-eeeeeeeee-8,8-eeeeeeeeeeeeee ee eeeeeeeee eeeeeeeeeeee ee 88% eeeeee (Meeeeee).

8-Meeeee-8M-eeeeeeeee-8,8-eeeeeeeeeeeeee (‌888‌, M8 = M; M8 = Me):[‌888‌]

Me e eeee ee M-eeeeeeeeeeeeeeeeeeeeeeeeeeeeee[‌888‌] (‌888‌, M8 = M; M8 = Me; 8.88 e, 8.88 eeee) eee eeeeeeeeeeee (8.88 e, 8.88 eeee) ee MMM (8 eM) eee eeeee MMM (8.88 e, 8.88 eeee), eee eee eeee eee eeeeeee ee 88°M. Meeeeeeeeeee eeeeeeeeeeeee eeeeee eeeeeeeee eeee eee eeee. Meeee eeeeeeee eee 8 e, eee eeee eee eeeeeee ee eeeeeeeeee eee eeeeee ee eee eeeeee eeee eeeeeee. Mee eeeeeeee eeeeeeee eee eeeeeeee eeee eeeeee eeee M8M (888 eM), eee eee eeeeeeeee eeeeeeeeeee eee eeeeeeeee eee eeeeeeeeeeeeee (eeeeeee, eeeeeeee) ee eeeeeeeee eeeeeeee; eeeee: 8.88 e (88%); ee 888–888°M.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8e, 88.