Science of Synthesis

Ishikawa, T., Science of Synthesis, (2004) 16, 1297.

Condensation of pyrimidine-4,5-diamines with 2-oxo aldehydes[‌45‌,‌63‌–‌71‌] and their equivalents[‌65‌,‌72‌–‌84‌] can theoretically lead to the formation of two isomeric products, 6- and 7-substituted pteridines. Although a mixture of the two possible products is obtained in many cases, in simple cases the 5-amino group of the pyrimidine preferentially reacts with the aldehyde group to give 7-substituted pteridines. The only pteridine product that forms in the reaction of pyrimidine-4,5-diamine with 2-oxopropanal is 7-methylpteridine in 60% yield.[‌45‌] Oxoacetaldehydes terminating in unsubstituted or 4-substituted phenyl groups afford the corresponding 7-arylpteridines ‌18‌ in high yields irrespective of the substituents on the phenyl ring (‌Scheme 13‌).[‌68‌]

‌Meeeee 88‌ 8-Meee-Meeeeeeeeee Meeeeeeeee eeee Meeeeeeeee-8,8-eeeeeeee eee Meee(eee)eeeeeeeeeeeee[‌88‌]

Mee eeeeeeee eeeeeeeeee eeeeeeeee eee eeeeee ee eeeeeee eeeeeeeee. Me eee eeee ee 8-eeeeeeeeeeeeeeee-8,8,8-eeeeeeee, eee eeeeeeee eeee 8-eeeeeeeeeee eeeee eeeeeee eeeeeeeeee eeeeeee 8-eeeeee-8-eeeeeeeeeeeeee-8-eeeee (‌88‌) ee 88% eeeee,[‌88‌] eeeeeee eee eeeeeeee 8-eeeeee eeeeeeeeee ‌88‌ ee eeeeee ee eee eeee eeeeeeee eeeeeee[‌88‌] ee eee eeeeeeee ee eeeeeeeee, eeeee eeeeee eeee eeeeee eeee eee eeeeeeee eeee eee eeeeee ee 8-eeeeeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeee ee Meeeeeeee ee eee Meeeeeee eeeeeee e Meeeeeeeee-8,8,8-eeeeeeee eee e 8-Mee Meeeeeee[‌88‌,‌88‌]

Me eee eeeeeeee ee 8,8-eeeeeeeeeeeeeeee-8(8M)-eee eeee 8-eeeeeeeeeee, 8-eeeeeeeeeeeeee-8(8M)-eee (‌88‌) ee eeeeee ee eee eeeeeeee ee eeeeee eeeeeeee eeeeeee; eeeeeee, eeeeeee eeeeeeeee ee 8-eeeeeeeeeee eeee eeeeee eeeeeeee eeeeeee eeeeee eeeeeeee, eeeeeee ee eee eeeeeeee 8-eeeeeeeeeeeeee-8(8M)-eee (‌88‌) eeeee eeeeeeee (‌Meeeee 88‌).[‌88‌]

‌Meeeee 88‌ Meeeee ee Meeeee Meeeeeee Meeeeee ee eee Meeeeeee ee 8,8-Meeeeeeeeeeeeeee-8(8M)-eee eee e 8-Mee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeeee

8-Meeeee-8-eeeeeeeeeeeeee-8-eeeee (‌88‌):[‌88‌]

Me e eeee ee 8-eeeeeeeeeeeeeeee-8,8,8-eeeeeeee (88.8 e, 8.88 eee) eee 88% MeMMM ee M8M (88 e, 8.8 eee) ee MeMM (888 eM) eee eeeee e eeee ee MMMe (88.8 e, 8.8 eee) eee MeMM (88 eM) ee M8M (888 eM). Meeee eee eeeeeee eee eeeeee ee e eeeee eeee eee 88 eee, e eeeeee eeeeeeeeeee eeeeeee eeeeee. Mee eeee eee eeeeee eee eeeeeeee, eee eeeee eeeeeee eee eeeeeeeee ee eee MMe, eeeeeee eeee eeeeeeee, eee eeee ee-eeeeeeeeeeee eeee 88% ee MeMM. Mee eeeeeee eee eeeeeeeeeeeeee (MMM) ee eeee eee eeeeeee ee eeee eeeeee eeeeeee; eeeee: 88.8 e (88%); ee 888–888°M (eee).

8-Meeeee-8-eeeeeeeeeeeeee-8-eeeee (‌88‌):[‌88‌]

M eeee ee 88% ee MeMMM (88.8 e, 8.88 eee) eee 88% ee M8MMM8 (88 e, 8.88 eee) (MMMMMMM: eeeeee eeeee) ee MeMM (888 eM) eeeee ee 88°M eee 88 eee. 8-Meeeeeeeeeeeeeee-8,8,8-eeeeeeee (88.8 e, 8.8 eee) eee MeMM (88 eM) eee eeeee, eee eee eeeeeee eee eeeeeeee eee 8 eee, eeee ee eee eeeeeee eeee M8M (88 eM), eee eeeeee eee 88 eee ee e eeeee eeee. Meeeeee, eeeeeeeee, eee eeeeeeeeeeeeeeeee (ee MMM) eeee eee eeeeeee; eeeee: 88.8 e (88%); ee 888–888°M.

8-Meeeeeeeeeeeee-8(8M)-eee (‌88‌):[‌88‌]

M eeeeeee ee 88% ee MeMMM (88 e, 8.8 eee) eee ee MeMMM8 (e 8.88; 888 eM) eee eeeee ee e eeee ee 8,8-eeeeeeeeeeeeeeee-8(8M)-eee (88 e, 8.88 eee) eee MeMMM8•M8M (88 e) ee M8M ee 88°M, eee eee eeeeeeeee eeeeeee eee eeee ee 88–88°M eee 88 e. Meeee eeeeeeee ee 88 M MMe (888 eM), eee eeeeeee eee eeeeeeeeeeee. Mee eeeeeeeee eeeee eee eeeeeeeee ee eeeeeeeeee, eeeeee eeee eeee M8M eee MeMM, eee eeeeee ee 888°M eee 88 eee; eeee eeeeeeee ee eee eeeeeeeee ee MM8 eee eeeeeeeee ee eeeeeeee-8(8M)-eee ‌88‌; eeeee: 88.8 e (88%); ee 888°M (eee; M8M eeee eeeeeeee).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8e, 888.