Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
16.13.1.1.2.6.7 Method 7: From 2-Aminobenzonitriles and Carbon Dioxide, Carbon Monoxide, Carbon Disulfide, or Potassium O-Ethyl Dithiocarbonate

DOI: 10.1055/sos-SD-016-00745

Kikelj, D.Science of Synthesis, (200416611.

The reaction of 2-aminobenzonitriles with carbon disulfide in pyridine solution constitutes a convenient, one-step synthesis of quinazoline-2,4(1H,3H)-dithiones 65 (X=Y=S) (Scheme 46).[‌235‌] The reaction proceeds by the intermediate formation of a 4-imino-1,4-dihydro-2H-3,1-benzothiazine-2-thione, which rearranges rapidly and irreversibly by a base-catalyzed ring openingring closure sequence to give 65. The method is generally applicable for the synthesis of fused pyrimidine-2,4-dithiones.[‌369‌] Quinazoline-2,4(1H,3H)-dithiones 65 (X=Y=S) are also obtained in the reaction of 2-aminobenzonitriles with potassium O-ethyl dithiocarbonate (potassium xanthate).[‌370‌] Carbon dioxide easily reacts with 2-aminobenzonitriles at room temperature, assisted by 1,8-diazabicyclo[5.4.0]undec-7-ene, to give quinazoline-2,4(1H,3H)-diones 65 (X=Y=O) in excellent yields.[‌371‌] Sulfur-assisted carbonylation of 2-aminobenzonitriles with carbon monoxide using potassium carbonate as a base or with carbonyl sulfide and 1,8-diazabicyclo[5.4.0]undec-7-ene as a base affords 4-thioxo-3,4-dihydroquinazolin-2(1H)-ones 65 (X=O; Y=S) under mild conditions.[‌372‌]

Meeeee 88 Meeeeeeeeee-8,8(8M,8M)-eeeeee, Meeeeeeeeee-8,8(8M,8M)-eeeeeeeee, eee 8-Meeeee-8,8-eeeeeeeeeeeeeeeee-8(8M)-eeee eeee 8-Meeeeeeeeeeeeeeeee eee Mee-Meeeee-Meee Meeeeeee Meeeeeee[‌888‌,‌888‌‌888‌]

Meeeeeeeeee 88

M8e M M Meeeeee Meeeeee Meee (°M) Meee (e) Meeee (%) ee (°M) Mee
M M M MM8 ee eeeeee 8 88 888888 [‌888‌]
M M M MMM MMM 88 88 888 888.8 [‌888‌]
8-(8-eeeeeeeeeeeeeeee) M M MM8 ee eeeeee 8 88 888888 [‌888‌]
8-MM8 M M MeMMM8M MeMM eeeeee 8 88 888 [‌888‌]
8-MM8 M M MM8 MMM 88 88 88 >888 [‌888‌]
8,8-(MMe)8 M M MM, M, M8MM8 MMM 88 8 888 888.8 [‌888‌]

e Meeeee ee eeeeeeeee ee 88.

Meeeeeeeeeee Meeeeeeee

Meeeeeeeeee-8,8(8M,8M)-eeeee (88, M8=M; M=M=M); Meeeeee Meeeeeeee:[‌888‌]

M MMM eeee (88eM) eeeeeeeeee 8-eeeeeeeeeeeeeeeee (8.88e, 88eeee) eee MMM (8.88eM, 88eeee) eee eeeeeeeeee eeeeeee eeeee MM8 (888Meee) ee 88°M eee 88e. Mee eeeeeee eee eeee eeeeee eeee 8M MMe (888eM) eee eee eeeee eeee eeeeeeeee eee eeeeee eeee eeeeeee (888eM) eee Me8M (888eM); eeeee: 8.88e (88%); ee >888°M.

Meeeeeeeeee-8,8(8M,8M)-eeeeeeee (88, M8=M; M=M=M); Meeeeee Meeeeeeee:[‌888‌]

M eeee ee 8-eeeeeeeeeeeeeeeee (8.8e, 88.8eeee) ee e eeeeeee ee eeeee eeeeeeee (88eM) eee MM8 (88eM) eee eeeeeeee eee 8e eee eeeeeee ee eeeee eeeeeeeee ee ee. Mee eeee eee eeeeeeee ee eeeeee eeeeee ee eeeeeeeee eeeeeeee eee eee eeeeeeee eeeeeee eeee MeMM (888eM). Mee eeeeee eeeeee eeeeeeeeeee ee eee eeeeeeee eee eeeeeeee eee, eeeeee eeee MeMM, eeee Me8M, eee eeeee; eeeee: 8.88e (88%); ee 888888°M (MeMM).

References


Cookie-Einstellungen