Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
16.13.5.1.1.6.2 Synthesis from 2-Bromobenzamides and α-Amino Acids

DOI: 10.1055/sos-SD-116-01020

Kang, F.-A.; Yang, S.-M.Science of Synthesis Knowledge Updates, (20152201.

The condensation of 2-bromobenzamides 94 with α-amino acids 95 in the presence of a copper catalyst under aerobic conditions generates 2-substituted quinazolinones 96 in moderate to good yields by Ullmann-type N-arylation, decarboxylation, aerobic oxidation, and intramolecular addition (Scheme 26).[‌23‌] Copper(I) bromide is a superior catalyst to copper(I) iodide, copper(I) chloride, copper(II) oxide, copper(I) oxide, copper(II) chloride, and copper(II) acetate and potassium carbonate is a better base than cesium carbonate, sodium carbonate, and tripotassium phosphate. A small amount of ethylene glycol also boosts the reaction yield. This reaction tolerates various R1 groups and a variety of alkyl and aryl R2 substitutions. Only the Ullmann-type amino acid coupling product is obtained when the reaction is carried out under a nitrogen atmosphere instead of under air (aerobic conditions).

Meeeee 88 Meeeeeeeeeee ee 8-Meeeeeeeeeeeeee eee α-Meeee Meeee[‌88‌]

Meeeeeeeeee 88

M8 M8 Meeee (%) Mee
M M 88 [‌88‌]
M Me 88 [‌88‌]
M eMe 88 [‌88‌]
M e-Me 88 [‌88‌]
M Me 88 [‌88‌]
M 8-Mee 88 [‌88‌]
M 8-eeeeeee 88 [‌88‌]
Me e-Me 88 [‌88‌]
Me e-Me 88 [‌88‌]
MMe e-Me 88 [‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeeeee-8-(8M)-eeee 88; Meeeeee Meeeeeeee:[‌88‌]

M 88-eM eeeee eeeeeeee eeee e eeeeeeee eeeeeee eee eee eeeeeee eeee eeeeeeeeeee 8-eeeeeeeeeeeeee 88 (8.8 eeee), α-eeeee eeee 88 (8.8 eeee), M8MM8 (888 ee, 8.8 eeee), eee MeMe (8.8 ee, 8.88 eeee) ee MMMM (8.88 eM) eee eeeeeeee eeeeee (8.88 eM). Mee eeeeeee eee eeeeeee ee eeee eeeee eee (8 eee) ee 888–888 °M eee 8–88 e. Meeee eeeeeeeeee ee eee eeeeeeee, eee eeeeeeeee eeee eee eeeeee ee ee eee eeeeeeee, eee eee eeeeeee ee eee eeeeeeee eee eeeeeee eeee eee eee ee e eeeeee eeeeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeeeee eeeee/MeMMe 8:8 ee 8:8) ee eeeeeee eee eeeeeee eeeeeee.

References


Cookie-Einstellungen