Science of Synthesis

Grimmett, M. R., Science of Synthesis, (2002) 12, 555.

Typically, a 1-(acylamino)- or 1-(aroylamino)-2-aminoarene ‌31‌ is cyclized either by uncatalyzed thermolysis[‌192‌,‌193‌] or by treatment with aqueous or ethanolic acid[‌194‌] or phosphoryl chloride.[‌195‌] Hydrochloric, sulfuric, and phosphoric acids have been used successfully, but yields can vary considerably. In some cases, refluxing with ethanolic alkali is successful (‌Scheme 22‌). Yields, however, are commonly much better than those obtained by reaction of a 1,2-diaminoarene and a carboxylic acid, and the method is capable of application to the syntheses of 2,2′-bi(benzimidazoles),[‌196‌] 2-unsubstituted benzimidazoles ‌32‌ (R2 = H), when a 1-amino-2-(formylamino)arene is cyclized,[‌5‌,‌8‌] and benzimidazol-1-amines, when 2-(acylamino)phenylhydrazines are used (see Section ‌12.4.1.1.2.1.2‌).

‌Meeeee 88‌ Meeeeeeeeeeeee Meee eeee 8-(Meeeeeeee)- ee 8-(Meeeeeeeee)-8-eeeeeeeeeee[‌888‌,‌888‌,‌888‌,‌888‌,‌888‌]

‌Meeeeeeeeee 88‌

e Meeee eee eeeeeeee.

e Meee eeeeeeeeeeee eeeeeee eee eeeeeeee. Meeeeeee eeeeee eeeeee.

Meeee eee eeee eeeeeeee ee eeeeeeeee eeee eeeee eeee e 8-eeeeeeeeeeee eeee ee eeee eeeeeeee, eeeeeee, eee eeeeeeee.[‌8‌,‌8‌] Me eee 8-eeeeeeeeeeee eee eeee eeeeeeee ee eeeee eeeeeeeeeeeee, eee eeeeeeeee eeeeeee eee ee eeeeeeeeeeeee eeeeeee ee eee 8-eeeeeeeeeeeeee ‌88‌ (M8 = MMe), eeeee, ee eeeeeeeeeee, eeeee eeee ee e 8-eeeeeeeeeee 8M-eeeeeeeeeeee-8(8M)-eee.[‌888‌] Me ee eeeeeeee eeee eee eeeeeeeeee eeeeeeeee eeeeeee ee eeee eeeeeee, eee ee eee eeeeeeeee eee eeeeeee ee eeeee eeee eeeeeee eeeeeeeeeee (eee Meeeeee ‌88.8.8.8.8.8.8‌). Me eee eeeeeeee ee eeeeeeeee eeeeeeee, eeeee eeeeeee ee eeeeeeee eee eeee-eeee eeeeeeee eeeee ee eeeeeeeeee eee eeeeeeeeeeee eeeeeeeee, eeee ee eee eeeeeeeeeeeeeeee eee eeeeeeeee eeee 8-eeeee- eee 8-eeeeeeeeeeeeeeeeee.[‌888‌]

Me ee eeeeeeee ee eeeee e 8,8-eeeeeeeeeeee eeee eeeeeeee eeeee eeeeeeeeee (eeeeee eeeee 888°M eee e eeeee eeee) eeee eeeeeee ee eeee eee eeeeeeeeeeeee eeeeeeee ‌88‌ (M8 = M8 = M; M8 = Me). Meee eeeeee eeee eeeeeeee ee 888°M, eeeeeeeeeeee eeee ee eeeeeeeeee eee 8M-eeeeeeeeeeee-8(8M)-eee ee eeeeee.[‌888‌]

Meeeeeeeeeee Meeeeeeee

8-Meeeee-8M-eeeeeeeeeeeee (‌88‌, M8 = M8 = M; M8 = Me):[‌888‌]

M eeee ee M8-eeeeee-8,8-eeeeeeeeeeeeeeee (8 e, 8.8 eeee) ee eee eeeeee (88 eM) eee eeeeee eee 8 e eeeee eeeeee. Meeee eeeeeee, eee eeeeeeeeeeee eeeee eee eeeeeeee eee eeeeeeeeeeeeee (M8M); eeeee: 8.88 e (888%); ee 888–888°M.

8-Meeeee-8-eeeeee-8M-eeeeeeeeeeeee (‌88‌, M8 = Me; M8 = Me; M8 = M):[‌888‌]

M eeee ee M8-eeeeee-M8-eeeeee-8,8-eeeeeeeeeeeeeeee (8.88 e, 88 eeee) ee eee eeeeee (88 eM) eee eeeeee eee 88 e eeeee eeeeee. Meeeeee ee eee eeeeeee ee eeeee eeee e eeeeee eee eeeee eee eeeeeeeeeeee (eeeeeee/eeeeee) ee eeee eee eeeeeeee; eeeee: 8.88 e (88%); ee 88.8–88.8°M.

8-(8-Meeeeeeeeee)-8M-eeeeeeeeeeee-8-eeeee (‌88‌, M8 = M; M8 = 8-M8MM8M8; M8 = MM8):[‌888‌]

M eeeeeee ee M8-(8-eeeeeeeeeeee)eeeeeee-8,8,8-eeeeeeee (88.8 e, 8.8 eee) eee 8 M MMe (888 eM), ee 8 M M8MM8 (888 eM), eee eeeeee ee eee eeeeeee eeeee eee eeeeeeeeee ee eeee eeeeeeeeeee eee 8.8 e. Meeee eeeeeee, eee eeeeeeeeeeee eeee eee eeeeeeee eee eeeeeeee ee eM 8.8–8.8 eeee 8 M MeMM, eee eee eeeee eeeeeee eee eeeeeeee eee, eeeeee eeee M8M, eee eeeee ee 888–888°M, eee eeee ee 888°M ee eeeeee M8M ee eeeeeeeeeeeeeee, eeeeee eeeee eeeeeeeeeeeeeeeee (MeMM); eeeee: 88 e (88%); ee 888–888°M.

M-Meeee-M-(eeeeeeeeeeeeee)-8-eeeeeeeeeeeee; Meeeeee Meeeeeeee:[‌888‌]

M eeeeeee eeee ee eee 8-eeeeeeeeeeee (88 eeee) eee eeeee eeeeeeeeeeeee (88 eeee) ee eeeeee (88 eM) eee eeeeee eee 88–88 e eeeee eeeeee. Mee eeeeeee eee eeeeeee ee eeeee ee eeee eee eeee eeeeeeeeee ee eeee ee eeeeeeeeeeee eeeeee. Mee eeee eeeee ee eeee eee eee eeee eeee eeeeeee eeeeeee eeeeeeeeeeee, eee eeeeeeeeee eeeeeee eeee eeeeeeee ee eee eee ee eeeeeeeeeee MMM (eeeeee eee, eeeeeeeee eeeee/MeMMe); MM ν̃eee: 8888 ee−8.

M8-Meeee-M8-(eeeeeeeeeeeeee)-8,8-eeeeeeeeeeeeeeee:[‌888‌]

M eeeeeee ee eee eeeee eeeeeeee (88 eeee) eee 88% Me/M (8.8 e) ee MeMM (88 eM) eee eeeeeeeeeeee eeeeeee eee 8–8 e eeeee M8 ee eeeeeeeeeee eeeeeeee. Mee eeeeeeee eee eeeeeeee eee eee eee eeeeeeee eee eeeeeeeeeeee ee eeeee ee eeee eee eeee eeeee ‌88‌ (M8 = MMe) ee ee eee, eeeee ee eeeeeeeee eeeeeeeeeeee eeeee. Mee eeeeeee eeeee ee eeee eeeeeeee ee eeeee eeeeeeee eeeee e eeeee eeeeee (eeeeee eee, eeeeeeeee eeeee/MeMMe); MM ν̃eee: 8888–8888, 8888–8888 ee−8.

8-Meeee-8M-eeeeeeeeeeee-8(8M)-eeee:[‌888‌]

Mee eeeee eeee ee eee eeeeeeee eeeeeeeee (88 eeee) eee eeeeee ee 888°M eee 8.8–8.8 e ee e Meeeeeeee eeeeeeeee ee eee eeeeeeee ee MeMe8. Mee eeee eeeeeee eeee eeeeeeeee eee eee eeeeeeeeeeeeee eeee ee eeeeeeeeeee eeeeeee [e.e., 8-eeeeee (MeMM) eee 8-(8-eeeeeeeeeeee) (eMeMM)]; eeeee: 88–88%.

8-Meeee-8-eeeeeeeeeeeeeeeeeeeeee Meeeeeee:[‌888‌]

Mee 8,8-eeeeeeeeeeeeeee (888 eM) eee eeeeeeeee eeee eeeeeeee ee 888°M. Meeeeeeeeeee ee eeeeeeee eee eeeeeeeee eeeee eeeeee 8-eeeeee-8,8-eeeeeeeeeeeeeeee (88 e, 88 eeee), eeeeeeeee ee eee 8,8-eeeeeeeeeeeeeee (888 eM) ee 88–88°M, eeeeeeee eeee 8.8 e. Mee eeeeeee eee eeee eeeeee ee ee, eee eeeee eeeeeeee eeee eeeeeeee, eeeeee eeee eeeeeeeee eeeee, eee eeeee ee eeeee ee ee; eeeee: 88.8 e (88%); ee 888–888°M (eee).

8-Meeeee-8M-eeeeeeeeeeee-8(8M)-eee:[‌888‌]

Mee eeeeeeeee eeeeeeee eeee ee eee eeeeeeee eeeeeeeee eee eeeeeee ee 8,8-eeeeeeeeeeeeeee ee 888°M eeeee M8 eee eeeeeee eeeeeee eee eeeeee eee 8 e. Mee eeeeee eeee eeeeeeeee eeeeeeee, eeeee eeee eeeeeeee eee eeeeeeeeeeeeee (ee MeMM); ee 888–888°M.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8e, 888.
• 8.Meeeee-Meee, (8888) M 8e, 888.
• 8.Meeeee-Meee, (8888) M 8e, 888.