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Example 30
To a stirred solution of 3-(3,4-dimethoxyphenyl)-5-(4-piperidyl)-1,2,4-oxadiazole (150 mg, 518 μmol) in N,N-dimethylformamide (1.50 mL) were added (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (196 mg, 518 μmol), N-ethyl-N-(propan-2-yl)propan-2-amine (201 mg, 1.56 mmol, 271 μL), and 2-(benzylamino)acetic acid (89 mg, 544 μmol). The mixture was stirred at 20° C. for 16 h and filtered, and the crude filtrate was purified directly by prep-HPLC (column: Luna C8 100×30 5 μm; mobile phase: [water (10 mM ammonium carbonate)-acetonitrile]; B%: 30%-60%, 12 min) to give 2-(benzylamino)-1-[4-[3-(3,4-dimethoxyphenyl)-1,2,4-oxadiazol-5-yl]-1-piperidyl]ethanone (48 mg, 110 μmol, 21%) as a yellow solid. 1H NMR (400 MHz, METHANOL-d4) δ=7.65 (dd, J=1.8, 8.2 Hz, 1H), 7.57 (d, J=1.8 Hz, 1H), 7.40-7.30 (m, 4H), 7.28-7.22 (m, 1H), 7.06 (d, J=8.4 Hz, 1H), 4.45 (br d, J=13.7 Hz, 1H), 3.94-3.83 (m, 7H), 3.78 (s, 2H), 3.57-3.44 (m, 2H), 3.40-3.33 (m, 1H), 3.27-3.20 (m, 1H), 3.01 (t, J=11.2 Hz, 1H), 2.17 (dd, J=2.8, 13.3 Hz, 2H), 1.93-1.73 (m, 2H); LCMS (ESI) m/z: [M+H]+=437.3.
Example 26
Synthesis of 169-A.
A mixture of tert-butyl hexahydropyrrolo[3,4-c]pyrrole-2(1H)-carboxylate (750 mg, 3.54 mmol), 1-methylpiperidin-4-one (800 mg, 7.08 mmol) and acetic acid (2 drops) in DCE (15 mL) was stirred at 50° C. for 2 h. Then Sodium triacetoxyborohydride (1.50 g, 7.08 mmol) was added into above mixture and stirred at 50° C. for another 2 h. After the reaction was completed according to LCMS, the solvent was diluted with water (10 mL) and then extracted by DCM (10 mL×3). The combined organics washed with brine (10 mL×3), dried over anhydrous Na2SO4 and then concentrated in vacuo. The residue was purified by column chromatography on silica gel (DCM:MeOH=100:1˜50:1) to give 169-A (750 mg, 69%) as a yellow oil.
Synthesis of 169-B.
A solution of 169-A (400 mg, 1.29 mmol) in DCM (10 mL) was added TFA (5 mL) and stirred at room temperature for 1 h. when LCMS showed the reaction was finished. The solvent was removed in vacuo to give 169-B as a crude product and used to next step directly.
Synthesis of 169-C.
A mixture of 143-C (306 mg, 0.65 mmol) and 169-B (crude product from last step) in acetonitrile (6 mL) was stirred at 50° C. for 30 min. Then Na2CO3 (624 mg, 6.50 mmol) was added into above mixture and stirred at 50° C. for 3 h. After the reaction was completed according to LCMS, the mixture was cooled to room temperature. The Na2CO3 was removed by filtered. The filtrate was concentrated in vacuo. The residue was purified by column chromatography on silica gel (DCM:MeOH=100:1˜20:1) to give 169-C (230 mg, 76%) as a yellow solid.
Synthesis of 169.
A mixture of 169-C (230 mg, 0.49 mmol) and Pd/C (230 mg) in MeOH (10 mL) was stirred at room temperature for 30 min under H2 atmosphere. Pd/C was then removed by filtration through the Celite. The filtrate was concentrated and the residue was purified by Pre-TLC (DCM:MeOH=10:1) to give 169 (150 mg, 70%) as a white solid.
Compounds 152, 182, 199, 201, 202, 203, 235, 236 and 256 were synthesized in a similar manner using the appropriately substituted aldehyde or ketone variant of 169.
Compound 152.
50 mg, 36%, a light yellow solid.
Compound 182.
70 mg, 38%, a red solid.
Compound 199.
50 mg, 54%, a light yellow solid.
Compound 201.
30 mg, 42%, as a yellow solid.
Compound 202.
30 mg, 42%, a yellow solid.
Compound 203.
30 mg, 18%, a yellow solid.
Compound 235.
170 mg, 87%, a white solid.
Compound 236.
70 mg, 50%, a white solid.
Compound 256.
20 mg, 8%, a light yellow solid.
Compounds 210, 211, 215, 222, 223, 242 and 262 were synthesized in a similar manner using the appropriately substituted amine variant of 169.
Compound 210.
160 mg, 96%, a tan solid.
Compound 211.
70 mg, 40%, a white solid
Compound 215.
70 mg, 75%, a white solid.
Compound 222.
30 mg, 42%, a yellow solid.
Compound 223.
35 mg, 31%, a white solid.
Compound 242.
50 mg, 34%, a white solid.
Compound 262.
38 mg, 43%, a white solid.
Example 41
Potassium carbonate (110 mg) was added to a solution of Compound 39 (200 mg) and ethyl 2-bromoacetate (100 mg) in DMF (5 mL), and the resulting mixture heated to 80° C. and stirred for 1 h under nitrogen protection. The reaction mixture was cooled to room temperature, and filtered. The filter cake was washed with ethyl acetate (2 mL). The filtrate was concentrated to obtain Compound 42-1. LCMS (ESI) m/z: 606 (M+1).
2) Synthesis of Compound 42-2
An aqueous solution of lithium hydroxide monohydrate (1M, 0.7 mL) was added to a solution of Compound 42-1 (200 mg) in tetrahydrofuran (5 mL), and the resulting mixture was stirred at 26° C. for 1 h under nitrogen protection. The reaction mixture was acidified to pH=5-6 with an aqueous solution of dilute hydrochloric acid (1M), and extracted with ethyl acetate (20 mL×3). The combined organic phase was washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to obtain Compound 42-2. LCMS (ESI) m/z: 578 (M+1).
3) Synthesis of Compound 42
Methylamine hydrochloride (18 mg) was added to a solution of Compound 42-2 (100 mg), HATU (80 mg), and triethylamine (50 mg, 494.12 μmol) in dichloromethane (5 mL), and the resulting mixture was stirred at 26° C. for 1 h. The reaction mixture was acidified to pH=5-6 with an aqueous solution of dilute hydrochloric acid (1M), and extracted with ethyl acetate (20 mL×3). The combined organic phase was washed with saturated brine (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated. The residue obtained from the concentration was purified by preparative TLC and preparative HPLC to obtain Compound 42. 1H NMR (400 MHz, CDCl3) δ ppm 8.68 (s, 1H), 7.95 (d, J=8.3 Hz, 1H), 7.88 (d, J=1.5 Hz, 1H), 7.76 (dd, J=8.3, 1.8 Hz, 1H), 7.31-7.36 (m, 1H), 7.29 (dd, J=8.8, 2.0 Hz, 1H), 4.51 (s, 2H), 2.90 (d, J=5.0 Hz, 3H), 2.84 (q, J=7.7 Hz, 2H), 1.62 (s, 6H), 1.29 ppm (t, J=7.5 Hz, 3H); LCMS (ESI) m/z: 591 (M+1).
Example 11
0.18 of 1-benzoyl-3-(5′-azido-1′-pentyl)pyrrolidine (14) was dissolved in 5 ml of tetrahydrofuran, and then 0.15 g of triphenylphosphine and 2 drops of water were added and refluxed overnight. After concentration under reduced pressure, 10 ml of dichloromethane was added, and washed sequentially with water and a saturated sodium chloride solution. The reaction solution was concentrated under reduced pressure, and separated by column chromatography (dichloromethane/methanol/aqueous ammonia=10:1:0.1 vol/vol/vol), to obtain 0.16 g of an oily product 1-benzoyl-3-(5′-amino-1′-pentyl)pyrrolidine (15). LCMS: 261[M+H].
The following compounds can be prepared according to the above method of preparing the compound 15 starting from the compound 12:
Example 22
To a stirred solution of 3-(3,4-dimethoxyphenyl)-5-(4-piperidyl)-1,2,4-oxadiazole (150 mg, 518 μmol) in N,N-dimethylformamide (2 mL) was added (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (196 mg, 518 μmol) and N-ethyl-N-(propan-2-yl)propan-2-amine (201 mg, 1.56 mmol, 271 μL) and 2-[benzoyl(methyl)amino]acetic acid (105 mg, 544 μmol). The mixture was stirred at 20° C. for 5 h, then cooled and purified directly by prep-HPLC (column: Luna C8 100×30 5 μm; mobile phase: [water (10 mM ammonium carbonate)-acetonitrile]; B%: 30%-60%, 12 min) to give N-[2-[4-[3-(3,4-dimethoxyphenyl) -1,2,4-oxadiazol-5-yl]-1-piperidyl]-2-oxo-ethyl]-N-methyl-benzamide (133 mg, 282 μmol, 54%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ=7.59 (dd, J=1.8, 8.4 Hz, 1H), 7.49-7.32 (m, 5H), 7.27 (br d, J=6.8 Hz, 1H), 7.16-7.08 (m, 1H), 4.44-4.24 (m, 2H), 4.21-4.03 (m, 1H), 4.02-3.88 (m, 1H), 3.88-3.74 (m, 6H), 3.56 (br d, J=13.7 Hz, 1H), 3.48-3.33 (m, 1H), 3.11-2.77 (m, 5H), 2.20-1.99 (m, 2H), 1.86 (br t, J=12.6 Hz, 1H), 1.74-1.48 (m, 2H), 1.43-1.26 (m, 1H); LCMS (ESI) m/z: [M+H]+=465.3.