METHOD OF 1,2,3,4,6,7,8,9-OCTAHYDRO-4a,5b,10,12-TETRAAZAINDENO[2,1-b]FLUOREN-5,11-DIONE SYNTHESIS Russian patent published in 2018 - IPC C07D471/22 

FIELD: chemistry.

SUBSTANCE: invention relates to a process for the preparation of 1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluoren-5,11-dione, which is that the preparation of 1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene is carried out during the reductive cyclization of 1,3-bis(piperidino)-4,6-dinitrobenzene in 36 % HCl, dropping 2.5 h at 20 °C 1 eq. SnCl₂⋅2H₂O, nitration of 1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene is carried out for 0.25 h at 20 °C with potassium nitrate in H₂SO₄ and molar ratio of 1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene : KNO₃ = 1:1.1, reduction of 11-nitro-1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene is carried out for 0.25 h at 50 °C with titanium (III) chloride and molar ratio of 11-nitro-1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene : TiCl₃ = 1:7, the oxidation of 11-amino-1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene is carried out with KNO₃ in H₂SO₄ at 20 °C for 4 hours and a molar ratio of 11-amino-1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene : KNO₃ = 1:10.

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EFFECT: new method for the preparation of 1,2,3,4,6,7,8,9-octahydro-4a,5b,10,12-tetraazaindeno[2,1-b]fluorene-5,11-dione is developed, which reduces the cost of synthesis, the number of stages and time of the process, increases the yield of the product.

1 cl, 4 ex