ethyl 4-hydroxy-1-benzofuran-6-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the compound obtained in the above (1) (24.7 g) in ethanol (150 mL) was added potassium carbonate (42.0 g), and the mixture was heated to reflux for 30 minutes. The reaction mixture was ice-cooled, and then acidified by 10% hydrochloric acid, and then extracted with ethyl acetate. The organic layer was washed with saturated saline, dried over sodium sulfate, and then concentrated under reduced pressure. The resulting residue was triturated with n-hexane-dichloromethane (5:1) to give ethyl 4-hydroxy-1-benzofuran-6-carboxylate [REx(7-1)] (19.6 g) as a pale yellow powder. the mixture was heated to reflux for 30 minutes cooled extracted with ethyl acetate The organic layer was washed with saturated saline dried over sodium sulfate concentrated under reduced pressure The resulting residue was triturated with n-hexane-dichloromethane (5:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of the compound obtained in the above (1) (24.7 g) in ethanol (150 mL) was added potassium carbonate (42.0 g), and the mixture was heated to reflux for 30 minutes. The reaction mixture was ice-cooled, and then acidified by 10% hydrochloric acid, and then extracted with ethyl acetate. The organic layer was washed with saturated saline, dried over sodium sulfate, and then concentrated under reduced pressure. The resulting residue was triturated with n-hexane-dichloromethane (5:1) to give ethyl 4-hydroxy-1-benzofuran-6-carboxylate [REx(7-1)] (19.6 g) as a pale yellow powder. the mixture was heated to reflux for 30 minutes cooled extracted with ethyl acetate The organic layer was washed with saturated saline dried over sodium sulfate concentrated under reduced pressure The resulting residue was triturated with n-hexane-dichloromethane (5:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was prepared in a similar manner as described for Example 341, from ethyl 4-hydroxy-benzofuran-6-carboxylate (8a) (0.26 g, 1.24 mmol), 2,4-difluoro-N,N-dimethylbenzamide (0.287 g, 1.55 mmol), and 2-amino-5-methyl pyridine (0.228 g, 2.11 mmol) (except that amide coupling was carried out at 75° C. for four hours) to give a solid (81 mg, 15% yield) as the expected product. 1H NMR (400 MHz, DMSO-d6) δ 10.84 (s, 1 H) 8.27 (s, 1 H) 8.22-8.23 (m, 1 H) 8.18-8.19 (m, 1 H)) 8.06-8.08 (d, 1 H) 7.67 (m, 1 H) 7.64 (m, 1 H) 7.39-7.44 (t, 1 H) 7.09-7.12 (m, 1 H) 6.95-6.97 (m, 1 H) 6.90 (m, 1 H) 3.00 (s, 3 H) 2.88 (m, 3 H) 2.28 (s, 3 H). LCMS for C24H20FN3O4 m/z 434.10 (M+H)+. The title compound was prepared in a similar manner

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Cs2CO3 (0.806 g, 2.47 mmol) was added to a solution of ethyl 4-hydroxy-benzofuran-6-carboxylate (8a) (0.256 g, 1.24 mmol) and 2,4-difluoro-N,N-dimethylbenzamide (0.287 g, 1.55 mmol) in DMF (5 mL). The mixture was stirred at 150° C. for 8 hours and then cooled to room temperature. 1-Methyl-1H-pyrazol-3-amine (0.21 g, 2.11 mmol) and then HATU (0.71 g, 1.87 mmol) were added. The reaction mixture was stirred at 50° C. for one hour and then filtered. Purification by HPLC gave a solid (200 mg, 39% yield) as the expected product. 1H NMR (400 MHz, DMSO-d6) δ 10.95 (s, 1 H) 8.22 (s, 1 H) 8.16 (m, 1 H)) 7.62-7.36 (s, 1 H) 7.60-7.61 (m, 1 H) 7.39-7.43 (m, 1 H) 7.08-7.11 (m, 1 H) 6.95-6.97 (m, 1 H) 6.89 (s, 1 H) 6.59-6.60 (m, 1 H) 3.78 (s, 3 H) 2.99 (s, 3 H) 2.88 (m, 3 H). LCMS for C22H19FN4O4 m/z 423.10 (M+H)+. cooled to room temperature The reaction mixture was stirred at 50° C. for one hour filtered Purification by HPLC

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was prepared in a similar manner as described for Intermediate 1f, from 4-fluorophenyl methyl sulfone (180 mg, 1.03 mmol), Cs2CO3 (630 mg, 1.93 mmol), and 4-hydroxy-benzofuran-6-carboxylic acid ethyl ester (8a) (199 mg, 0.97 mmol). Purification by flash column chromatography eluting with 15% EtOAc in hexanes gave a pale yellow oil (261 mg, 75% yield). 1H NMR (400 MHz, CDCl3) δ 8.13 (s, 1 H) 7.91 (s, 2 H) 7.74 (s, 1 H) 7.65 (s, 1 H) 7.13 (s, 2 H) 6.66 (s, 1 H) 4.41 (s, 2 H) 3.08 (s, 3 H) 1.42 (s, 3 H); LCMS for C18H1606S m/z 383.00 (M+Na)+. Purification by flash column chromatography eluting with 15% EtOAc in hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pd on carbon (100 mg) was added to a solution of 4-hydroxy-benzofuran-6-carboxylic acid ethyl ester (8a) (333 mg, 1.61 mmol) in acetic acid. The mixture was stirred under H2 (50 psi) for 48 hr. The mixture was filtered through Celite and concentrated. The residue was taken into saturated aqueous NaHCO3 and extracted with EtOAc. The organic layers were dried over MgSO4 and concentrated. The residue was purified by flash column chromatography eluting with 15% EtOAc in hexanes to give a pale yellow solid (315 mg, 94% yield). 1H NMR (400 MHz, CDCl3) δ 7.16 (d, J=1.26 Hz, 1 H) 7.05 (s, 1 H) 4.65 (t, J=8.72 Hz, 2 H) 4.35 (q, J=7.07 Hz, 2 H) 3.21 (t, J=8.72 Hz, 2 H) 1.38 (t, J=7.07 Hz, 3 H); LCMS for C11H12O4 m/z 209.10 (M+H)+. The mixture was filtered through Celite concentrated extracted with EtOAc The organic layers were dried over MgSO4 concentrated The residue was purified by flash column chromatography eluting with 15% EtOAc in hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: t-Butoxide (1.7 g, 15 mmol) was added to a solution of 2-furaldehyde (2.5 mL, 30.2 mmol) and diethyl succinate (3.2 mL, 19 mmol) in t-butanol (20 mL). The mixture was refluxed for 2 hr, cooled to room temperature and acidified with aqueous HCl (20% v/v) to Ph ˜2. The mixture was diluted with 5% HCl (100 mL) and extracted with EtOAc (2×100 mL). The organic layers were then extracted with 10% aqueous solution of Na2CO3 (2×100 mL). The aqueous solution was washed with EtOAc and then acidified with 20% HCl to Ph ˜2. The aqueous layer was finally extracted with EtOAc (3×100 mL), dried over MgSO4 and concentrated to give a brown oil. The crude product was dissolved in Ac2O (10 mL) and added NaOAc (1.6 g, 19 mmol). The mixture was heated to reflux for 5 hr, cooled to room temperature and concentrated. The residue was taken into ½ saturated Na2CO3, extracted with EtOAc (2×150 mL), dried over MgSO4 and concentrated to give a brown color solid. The solid was then dissolved in EtOH (10 mL). To the solution was added K2CO3 (2.5 g, 18 mmol). The resulting reaction mixture was heated to reflux overnight and the solvent was removed in vacuo. The brown residue was then treated with H2O (50 mL) and acidified with 6N HCl to pH 6. The solution was then extracted with EtOAc (2×50 mL), and combined organic layers were dried over MgSO4 and concentrated. The crude material was purified by flash column chromatography to give a yellow color solid (532 mg, 9% yield). 1H NMR (400 MHz, CDCl3) δ 7.83 (s, 1 H) 7.68 (d, J=2.02 Hz, 1 H) 7.51 (s, 1 H) 6.92-7.00 (m, 1 H) 4.42 (q, J=7.24 Hz, 2 H) 1.42 (t, J=7.20 Hz, 3 H). The mixture was refluxed for 2 hr extracted with EtOAc (2×100 mL) The organic layers were then extracted with 10% aqueous solution of Na2CO3 (2×100 mL) The aqueous solution was washed with EtOAc The aqueous layer was finally extracted with EtOAc (3×100 mL) dried over MgSO4 concentrated to give a brown oil The mixture was heated to reflux for 5 hr cooled to room temperature concentrated extracted with EtOAc (2×150 mL) dried over MgSO4 concentrated to give a brown color solid The resulting reaction mixture was heated to reflux overnight the solvent was removed in vacuo The brown residue was then treated with H2O (50 mL) The solution was then extracted with EtOAc (2×50 mL) were dried over MgSO4 concentrated The crude material was purified by flash column chromatography

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Cs2CO3 (0.806 g, 2.47 mmol) was added to a solution of ethyl 4-hydroxybenzofuran-6-carboxylate (8a) (0.27 g, 1.24 mmol) and 1-fluoro-4-(methylsulfonyl)benzene (0.22 g, 1.26 mmol) in DMF (5 mL). The mixture was stirred at 120° C. for 8 hours and then cooled to room temperature. 1-Methyl-1H-pyrazol-3-amine (0.18 g, 1.85 mmol) and HATU (0.7 g, 1.85 mmol) were added. The reaction mixture was stirred at 50° C. for one hour and then filtered. Purification by HPLC gave a solid (103 mg, 21% yield) as the expected product. 1H NMR (400 MHz, DMSO-d6) δ 10.97 (s, 1 H) 8.24-8.26 (m, 1 H) 8.17-8.19 (m, 1 H) 7.92-7.97 (m, 2 H) 7.65-7.67 (m, 1 H) 7.60-7.61 (m, 2 H) 7.25-7.29 (m, 1 H) 6.87-6.88 (m, 1 H) 6.58 (m, 1 H) 3.78 (s, 3 H), 3.21 (s, 3 H), 2.58 (m, 3 H). LCMS for C20H17N3O5S m/z 412.10 (M+H)+. cooled to room temperature The reaction mixture was stirred at 50° C. for one hour filtered Purification by HPLC

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was prepared in a similar manner as described for Example 341, from ethyl 4-hydroxy-benzofuran-6-carboxylate (8a) (0.26 g, 1.24 mmol), 2,4-difluoro-N,N-dimethylbenzamide (0.287 g, 1.55 mmol), and 2-amino-5-methylpyridine (0.228 g, 2.11 mmol) (except that amide coupling was carried out at 75° C. for four hours) to give a solid (81 mg, 15% yield) as the expected product. 1H NMR (400 MHz, DMSO-d6) δ 10.84 (s, 1 H) 8.27 (s, 1 H) 8.22-8.23 (m, 1 H) 8.18-8.19 (m, 1 H)) 8.06-8.08 (d, 1 H) 7.67 (m, 1 H) 7.64 (m, 1 H) 7.39-7.44 (t, 1 H) 7.09-7.12 (m, 1 H) 6.95-6.97 (m, 1 H) 6.90 (m, 1H) 3.00 (s, 3 H) 2.88 (m, 3 H) 2.28 (s, 3 H). LCMS for C24H20FN3O4 m/z 434.10 (M+H)+. The title compound was prepared in a similar manner

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Cs2CO3 (0.806 g, 2.47 mmol) was added to a solution of ethyl 4-hydroxy-benzofuran-6-carboxylate (8a) (0.256 g, 1.24 mmol) and 2,4-difluoro-N,N-dimethylbenzamide (0.287 g, 1.55 mmol) in DMF (5 mL). The mixture was stirred at 150° C. for 8 hours and then cooled to room temperature. 1-Methyl-1H-pyrazol-3-amine (0.21 g, 2.11 mmol) and then HATU (0.71 g, 1.87 mmol) were added. The reaction mixture was stirred at 50° C. for one hour and then filtered. Purification by HPLC gave a solid (200 mg, 39% yield) as the expected product. 1H NMR (400 MHz, DMSO-d6) δ 10.95 (s, 1 H) 8.22 (s, 1 H) 8.16 (m, 1 H)) 7.62-7.36 (s, 1 H) 7.60-7.61 (m, 1 H) 7.39-7.43 (m, 1 H) 7.08-7.11 (m, 1 H) 6.95-6.97 (m, 1 H) 6.89 (s, 1 H) 6.59-6.60 (m, 1 H) 3.78 (s, 3 H) 2.99 (s, 3 H) 2.88 (m, 3 H). LCMS for C22H19FN4O4 m/z 423.10 (M+H)+. cooled to room temperature The reaction mixture was stirred at 50° C. for one hour filtered Purification by HPLC

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was prepared in a similar manner as described for Intermediate 1f, from 4-fluorophenyl methyl sulfone (180 mg, 1.03 mmol), Cs2CO3 (630 mg, 1.93 mmol), and 4-hydroxy-benzofuran-6-carboxylic acid ethyl ester (8a) (199 mg, 0.97 mmol). Purification by flash column chromatography eluting with 15% EtOAc in hexanes gave a pale yellow oil (261 mg, 75% yield). 1H NMR (400 MHz, CDCl3) δ 8.13 (s, 1 H) 7.91 (s, 2 H) 7.74 (s, 1 H) 7.65 (s, 1 H) 7.13 (s, 2 H) 6.66 (s, 1 H) 4.41 (s, 2 H) 3.08 (s, 3 H) 1.42 (s, 3 H); LCMS for C18H16O6S m/z 383.00 (M+Na)+. Purification by flash column chromatography eluting with 15% EtOAc in hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pd on carbon (100 mg) was added to a solution of 4-hydroxy-benzofuran-6-carboxylic acid ethyl ester (8a) (333 mg, 1.61 mmol) in acetic acid. The mixture was stirred under H2 (50 psi) for 48 hr. The mixture was filtered through Celite and concentrated. The residue was taken into saturated aqueous NaHCO3 and extracted with EtOAc. The organic layers were dried over MgSO4 and concentrated. The residue was purified by flash column chromatography eluting with 15% EtOAc in hexanes to give a pale yellow solid (315 mg, 94% yield). 1H NMR (400 MHz, CDCl3) δ 7.16 (d, J=1.26 Hz, 1 H) 7.05 (s, 1 H) 4.65 (t, J=8.72 Hz, 2 H) 4.35 (q, J=7.07 Hz, 2 H) 3.21 (t, J=8.72 Hz, 2 H) 1.38 (t, J=7.07 Hz, 3 H); LCMS for C11H12O4 m/z 209.10 (M+H)+. The mixture was filtered through Celite concentrated extracted with EtOAc The organic layers were dried over MgSO4 concentrated The residue was purified by flash column chromatography eluting with 15% EtOAc in hexanes