methyl 8,8-dioxo-8lambda6-thia-2,3,5,7-tetraazatricyclo[7.4.0.0,2,6]trideca-1(13),3,5,9,11-pentaene-4-carboxylate synthesis

Yield:1311315-62-4 76%

Reaction Conditions:

with potassium carbonate in N,N-dimethyl-formamide at 20 - 80; for 10 h;

Steps:

General procedure for the preparation of annulated azolo[c][1,2,4]benzothiadiazine 5,5-dioxides 3 and 6 from sulfonyl chlorides 1а-1с, 1f, 1i and 5-aminoazoles 2, 5a-c

General procedure: To a stirred solution of a 5-aminoazole (0.005 mol) and potassium carbonate (1.38 g, 0.01 mol) in DMF (50 mL) a solution of sulfonyl chloride (0.005 mol) in DMF (50 mL) was added drop wise. The reaction mixture was stirred for 2 h at room temperature and then for 8 h at 80 °C. The solvent was removed under reduced pressure and the residue was dissolved in deionized water (200 mL). The pH of the solution was adjusted to 1 with concentrated hydrochloric acid causing precipitation of a colorless solid. The precipitate was filtered and washed with water (3x75 mL) and with 2-propanol (2x10 mL).

References:

Cherepakha, Artem;Kovtunenko, Vladimir O.;Tolmachev, Andrey [Tetrahedron Letters,2013,vol. 54,# 8,p. 986 - 988] Location in patent:supporting information