ChemicalBook CAS DataBase List 3-CHLORO-6,7-DIHYDRO-5H-BENZO[6,7]CYCLOHEPTA[1,2-C]PYRIDAZINE

3-CHLORO-6,7-DIHYDRO-5H-BENZO[6,7]CYCLOHEPTA[1,2-C]PYRIDAZINE synthesis

5synthesis methods

Product Name:3-CHLORO-6,7-DIHYDRO-5H-BENZO[6,7]CYCLOHEPTA[1,2-C]PYRIDAZINE
CAS Number:25823-53-4
Molecular formula:C13H11ClN2
Molecular Weight:230.69

25823-52-3 Synthesis

6,7-dihydro-2H-benzo[6,7]cyclohepta[1,2-c]pyridazin-3(5H)-one

25823-52-3
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$73.00/100mg

3-CHLORO-6,7-DIHYDRO-5H-BENZO[6,7]CYCLOHEPTA[1,2-C]PYRIDAZINE

25823-53-4
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$65.00/10mg

Yield:25823-53-4 99%

Reaction Conditions:

Stage #1: 2,5,6,7-tetrahydro-3H-benzo[6,7]cyclohepta[1,2-c]pyridazin-3-onewith trichlorophosphate at 100; for 2 - 4.75 h;Heating / reflux;
Stage #2: with water;sodium hydrogencarbonate at 0;Product distribution / selectivity;

Steps:

8.A; 8.B

SYNTHETIC PREPARATION 8; Synthesis of 3-chloro-6,7-dihydro-5H-benzo[6,7]cyclohepta[1 ,2-c]pyridazine Compound of formula (Df)A. A mixture of the compound of formula (De), 3-oxo-6,7-dihydro-5/-/- benzo[6,7]cyclohepta[1 ,2-c]pyridazine (4.0 g, 19.3 mmol) and POCI₃ (20 ml_) was refluxed for 2 h. After cooling to ambient temperature, the volatiles were evaporated. The residue was poured into a mixture of ice water and sodium bicarbonate, CH₂CI₂ (200 ml_) was added to dissolve the solid. The layers were separated, and the aqueous layer was extracted with CH₂CI₂ one more time. The combined organic layers were washed with brine. After being dried (MgSO₄), filtered, and concentrated, the compound of formula (Df), 3-chloro-6,7-dihydro-5H-benzo[6,7]cyclohepta[1 ,2- φyridazine was obtained as a yellow solid (4.3 g, 99%), ¹H NMR (300 MHz, CDCI₃) δ: 7.82 (m, 1 H), 7.45-7.24 (m, 4H), 2.59-2.51 (m, 4H), 2.27 (quant, J = 6.9 Hz, 2H); LC- MS: purity: 100%; MS (m/e): 231 (MH⁺).B. Alternatively, 3-Oxo-6,7-dihydro-5H-benzo[6,7]cyclohepta[1 ,2- c]pyridazine was heated with 20 ml. of phosphorus (III) oxychloride at 100 ⁰C for 4.75 h. The solvent was removed under vacuum. The residue was treated with ice and saturated sodium bicarbonate solution. The solid which formed was filtered off, washed well with water and air-dried to yield the corresponding 3-chloro-6,7-dihydro- 5H-benzo[6,7]cyclohepta[1 ,2-c]pyridazine (1.6 g); ¹H NMR (CDCI₃, 300 MHz) 7.82 (m, 1 H), 7.44 (m, 2H), 7.39 (s, 1 H), 7.27 (m, 1 H), 2.55 (m, 4H), 2.32 (m, 2H) ppm; MS (ES) 231/233 (M+H).