3,4-Dinitrophenol → HCID 57637399, compound

Temperature

100 °C

To a stirred solution of 3,4-dinitrophenol (2 g, 10.9 mmol, 1 eq) in dimethyl formamide (40 ml), chloropropyl piperidine hydrochloride (2.8 g, 14.2 mmol, 1.3 eq) and potassium carbonate (3.2 g, 22.9 mmol, 2.1 eq) were added. The mixture was heated to 100° C. for 4 hours and the reaction was cooled to room temperature. The mixture was passed through a SCX column and eluted with 7N ammonia in methanol, the eluent was concentrated and the residue was subjected to chromatography on silica gel (100 g) to yield 1-[3-(3,4-dinitro-phenoxy)-propyl]-piperidine [3.45 g] as a yellow oil. Step 2. 1-[3-(3,4-Dinitro-phenoxy)-propyl]-piperidine [3.2 g] was dissolved in methanol (20 ml) and palladium on carbon (1.12 g, 10%) and formic acid (2 ml) was added. The mixture was hydrogenated at 50 psi for 3 hours and the mixture was filtered through celite. The filtrate was concentrated to afford 4-(3-piperidin-1-yl-propoxy)-benzene-1,2-diamine [2.45 g, Intermediate (39)] product as a dark oil. LC/MS: 250 (M+H). Step 3. A mixture of 4-(3-piperidin-1-yl-propoxy)-benzene-1,2-diamine [2.2 g, Intermediate (39)] and formic acid (20 ml) at 100° C. was stirred for 3 hours and then cooled to room temperature and passed through a SCX column. The column was eluted with 7N ammonia in methanol to yield 6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazole [3.45 g, Intermediate (40)] as a dark oil.; LC/MS: 260 (M+H). Step 4. To a stirred solution of 6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazole [2.6 g, Intermediate (40)] in dimethyl formamide (20 ml), sodium hydride (0.44 g, 60% dispersion in oil) in two portions was added under nitrogen followed by benzyl-chloromethyl ether (1.89 g) in dimethyl formamide (5 ml) in a dropwise manner. The reaction mixture was stirred at room temperature overnight, then poured into water (150 ml) and then extracted three times with ethyl acetate (50 ml). The combined extracts were washed with water and brine, dried over magnesium sulfate, filtered and concentrated. Chromatography on silica gel yields 1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazole [5.7 g, Intermediate (41)]. LC/MS: 380 (M+H). Step 5. 1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazole [460 mg, Intermediate (41)] was dissolved in tetrahydrofuran (15 ml, dry) under nitrogen and the solution was cooled to 0° C. n-Butylithium (2 ml, 1.3 mmol, 2.4 eq) was added and the solution was stirred for 0.5 hour. Then, the mixture was warmed to room temperature, and a second portion of n-butylithium (1 ml, 1.2 eq) was added and stirring was continued for 0.5 hour. Then 3-bromo-benzo[b]thiophene-2-carboxylic acid methoxy-methyl-amide (401 mg, 1.1 eq) was added and the new solution was stirred at room temperature overnight. The solution was passed through a SCX column and the residue was subjected to chromatography to yield [1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-(3-bromo-benzo[b]thiophen-2-yl)-methanone [40 mg, Intermediate (42)]. Step 6. A mixture of [1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-(3-bromo-benzo[b]thiophen-2-yl)-methanone [40 mg, Intermediate (42)], benzophenone hydrazone (18 mg, 1.4 eq), Pd(OAc) (0.9 mg, 0.05 eq)), DPPF(3.8 mg, 0.1 eq) and cesium carbonate (33.7 mg, 1.6 eq) in 5 ml toluene under nitrogen was heated at 90° C. overnight. The reaction was cooled to room temperature and the mixture was passed through a SCX column and eluted with 7N ammonia in methanol to yield [3-(N′-benzhydrylidene-hydrazino)-benzo[b]thiophen-2-yl]-[1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-methanone [200 mg, Intermediate (43)]. Step 7. A mixture of [3-(N′-benzhydrylidene-hydrazino)-benzo[b]thiophen-2-yl]-[1-benzyloxymethyl-6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-methanone [200 mg, Intermediate (43)] and concentrated HBr (2 ml) in ethanol (4 ml) was heated at 90° C. overnight. The solution cooled to room temperature and the mixture was passed through a SCX column. Eluting with 7N ammonia in methanol yields 3-[6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-1H-benzo[4,5]thieno[3,2-c]pyrazole (72.1 mg). This material was dissolved in HCl/1,4-dioxane (2 ml, 4M) and methanol (0.05 ml) and the mixture was concentrated and dried to afford 3-[6-(3-piperidin-1-yl-propoxy)-1H-benzoimidazol-2-yl]-1H-benzoimidazol-2-yl]-1H-benzo[4,5]thieno[3,2-c]pyrazole hydrochloride [85.1 mg, Example 55]. LC/MS: 432 (M+H), RT=2.49 minutes; 1H NMR [(CD3)2SO]: δ 9.6 (1H, s), 8.0 (1H, t), 7.4 (2H, m), 7.3 (1H, s), 7.2 (1H, m), 6.9 (1H, m), 6.8 (1H, m), 4.2 (2H, t), 3.6-3.7 (4H, m), 3.5-3.6 (2H, m), 3.4 (1H, m), 3.2 (1H, m), 2.8 (2H, m), 2.2 (2H, m), 1.8 (1H, m), 1.4(1H, m).

1. temperaturethe reaction was cooled to room temperature
2. washeluted with 7N ammonia in methanol
3. concentrationthe eluent was concentrated

ORD record

ord-97be08e59ac046adada03c6b659e883b

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07518000B2