2-amino-4-ethylphenol

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a mixture of 2-amino-4-ethylphenol (0.89 g, 0.0065 mol) in tetrahydrofuran (80 mL) was added 4-bromophenyl isothiocyanate (1.4 g, 0.0065 mol) at room temperature. The mixture was stirred for 2 hours at room temperature. Anhydrous copper sulfate (6.2 g, 0.039 mol), triethylamine (0.9 mL, 0.0065 mol) and silica gel (11.7 g) were added to the reaction mixture. The mixture was stirred for 4 hours at room temperature. The solvent was removed under reduced pressure. The mixture was filtered through silica gel pad using 25% ethyl acetate/n-heptane as a mobile phase to give brown colored solid. The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase. The solvent was removed, and the residue was triturated with n-heptane to give N2-(4-bromophenyl)-5-ethyl-1,3-benzoxazol-2-amine (0.96 g, 0.003 mol). RP-HPLC (Delta Pak C18, 5 μm, 300 A, 15 cm; 5%-95% acetonitrile-0.1M ammonium acetate over 10 min, 1 mL/min) Rt 12.1 min. MS: MH+: 318 The mixture was stirred for 4 hours at room temperature The solvent was removed under reduced pressure The mixture was filtered through silica gel pad to give brown colored solid The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase The solvent was removed the residue was triturated with n-heptane

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

Procedure: To a mixture of 2-amino-4-ethylphenol (0.89 g, 0.0065 mol) in tetrahydrofuran (80 mL) was added 4-bromophenyl isothiocyanate (1.4 g, 0.0065 mol) at room temperature. The mixture was stirred for 2 hours at room temperature. Anhydrous copper sulfate (6.2 g, 0.039 mol), triethylamine (0.9 mL, 0.0065 mol) and silica gel (11.7 g) were added to the reaction mixture. The mixture was stirred for 4 hours at room temperature. The solvent was removed under reduced pressure. The mixture was filtered through silica gel pad using 25% ethyl acetate/n-heptane as a mobile phase to give brown colored solid. The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase. The solvent was removed, and the residue was triturated with n-heptane to give N2-(4-bromophenyl)-5-ethyl-1,3-benzoxazol-2-amine (0.96 g, 0.003 mol). RP-HPLC (Delta Pak C18, 5 μm, 300 A, 15 cm; 5%-95% acetonitrile-0.1M ammonium acetate over 10 min, 1 mL/min) Rt 12.1 min. MS: MH+: 318 The mixture was stirred for 4 hours at room temperature The solvent was removed under reduced pressure The mixture was filtered through silica gel pad to give brown colored solid The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase The solvent was removed the residue was triturated with n-heptane

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 4-ethyl-2-nitrophenol (5.5 g, 0.032 mol) in ethanol (180 mL) and water (90 mL) was added sodium thiosulfate (23 g, 0.131 mol) at room temperature. The heterogeneous mixture was stirred at 80° C. under an atmosphere of nitrogen for 16 hour. The reaction mixture was cooled to room temperature, and ethanol was removed under reduced pressure. The aqueous layer was extracted with ethyl acetate (3×100 mL), and the organic layer was washed with brine and dried under sodium sulfate. The solvent was removed under reduced pressure, and the residue was purified by flash column chromatography on silica using 0%-25% methanol/dichloromethane as a mobile phase (×2). The solvent was removed under reduced pressure to give 2-amino-4-ethylphenol (0.89 g, 0.006 mol). 1H NMR (DMSO-d6, 400 MHz) δ 8.61 (br, 2H), 6.47 (d, 1H), 6.37 (s, 1H), 6.18 (d, 1H), 2.17 (q, 2H), 1.08 (t, 3H). MS: MH−: 137 The reaction mixture was cooled to room temperature ethanol was removed under reduced pressure The aqueous layer was extracted with ethyl acetate (3×100 mL) the organic layer was washed with brine dried under sodium sulfate The solvent was removed under reduced pressure the residue was purified by flash column chromatography on silica using 0%-25% methanol/dichloromethane as a mobile phase (×2) The solvent was removed under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 8.2 g (0.06 M) 2-amino-4-ethylphenol and 5.4 g (0.09 M) urea were thoroughly mixed and heated in an oil bath to 180° C. for 2.0 hours. Thereafter the mixture was allowed to cool to 100° C. HCl solution (1.0 normal) was added to the mixture while stirring and the mixture was cooled to room temperature. The cooled mixture was extracted three times with methylene chloride. The combined organic phases were dried and stripped in vacuum. The sample yielded 5.9 g dark solid with a melting point of 75°-77° C. Spectroscopic data: nuclear magnetic resonance (NMR), C-13 NMR, infrared, and mass spectroscopy are consistent with the proposed structure. to cool to 100° C the mixture was cooled to room temperature The cooled mixture was extracted three times with methylene chloride The combined organic phases were dried

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 8.2 g (0.06 M) 2-amino-4-ethylphenol and 5.4 g (0.09 M) urea were thoroughly mixed and heated in an oil bath to 180° C. for 2.0 hours. Thereafter the mixture was allowed to cool to 100° C. HCl solution (1.0 normal) was added to the mixture while stirring and the mixture was cooled to room temperature. The cooled mixture was extracted three times with methylene chloride. The combined organic phases were dried and stripped in vacuum. The sample yielded 5.9 g dark solid with a melting point of 75°-77° C. Spectroscopic data: nuclear magnetic resonance (NMR), C-13 NMR, infrared, and mass spectroscopy are consistent with the proposed structure. to cool to 100° C the mixture was cooled to room temperature The cooled mixture was extracted three times with methylene chloride The combined organic phases were dried

Conditions: temp:180.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 8.2 g (0.06 M) 2-amino-4-ethylphenol and 5.4 g (0.09 M) urea were thoroughly mixed and heated in an oil bath to 180° C. for 2.0 hours. Thereafter the mixture was allowed to cool to 100° C. HCl solution (1.0 normal) was added to the mixture while stirring and the mixture was cooled to room temperature. The cooled mixture was extracted three times with methylene chloride. The combined organic phases were dried and stripped in vacuum. The sample yielded 5.9 g dark solid with a melting point of 75°-77° C. Spectroscopic data: nuclear magnetic resonance (NMR), C-13 NMR, infrared, and mass spectroscopy are consistent with the proposed structure. to cool to 100° C the mixture was cooled to room temperature The cooled mixture was extracted three times with methylene chloride The combined organic phases were dried

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

Procedure: To a mixture of 2-amino-4-ethylphenol (0.89 g, 0.0065 mol) in tetrahydrofuran (80 mL) was added 4-bromophenyl isothiocyanate (1.4 g, 0.0065 mol) at room temperature. The mixture was stirred for 2 hours at room temperature. Anhydrous copper sulfate (6.2 g, 0.039 mol), triethylamine (0.9 mL, 0.0065 mol) and silica gel (11.7 g) were added to the reaction mixture. The mixture was stirred for 4 hours at room temperature. The solvent was removed under reduced pressure. The mixture was filtered through silica gel pad using 25% ethyl acetate/n-heptane as a mobile phase to give brown colored solid. The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase. The solvent was removed, and the residue was triturated with n-heptane to give N2-(4-bromophenyl)-5-ethyl-1,3-benzoxazol-2-amine (0.96 g, 0.003 mol). RP-HPLC (Delta Pak C18, 5 μm, 300A, 15 cm; 5%-95% acetonitrile—0.1M ammonium acetate over 10 min, 1 mL/min) Rt 12.1 min. MS: MH+: 318 The mixture was stirred for 4 hours at room temperature The solvent was removed under reduced pressure The mixture was filtered through silica gel pad to give brown colored solid The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase The solvent was removed the residue was triturated with n-heptane

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 4-ethyl-2-nitrophenol (5.5 g, 0.032 mol) in ethanol (180 mL) and water (90 mL) was added sodium thiosulfate (23 g, 0.131 mol) at room temperature. The heterogeneous mixture was stirred at 80° C. under an atmosphere of nitrogen for 16 hour. The reaction mixture was cooled to room temperature, and ethanol was removed under reduced pressure. The aqueous layer was extracted with ethyl acetate (3×100 mL), and the organic layer was washed with brine and dried under sodium sulfate. The solvent was removed under reduced pressure, and the residue was purified by flash column chromatography on silica using 0%-25% methanol/dichloromethane as a mobile phase (×2). The solvent was removed under reduced pressure to give 2-amino-4-ethylphenol (0.89 g, 0.006 mol). 1H NMR (DMSO-d6, 400 MHz) δ 8.61 (br, 2H), 6.47 (d, 1H), 6.37 (s, 1H), 6.18 (d, 1H), 2.17 (q, 2H), 1.08 (t, 3H). MS: MH−: 137 The reaction mixture was cooled to room temperature ethanol was removed under reduced pressure The aqueous layer was extracted with ethyl acetate (3×100 mL) the organic layer was washed with brine dried under sodium sulfate The solvent was removed under reduced pressure the residue was purified by flash column chromatography on silica using 0%-25% methanol/dichloromethane as a mobile phase (×2) The solvent was removed under reduced pressure

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

Procedure: To 2-methyl-1-(tetrahydropyran-4-yl)benzimidazole-5-carboxylic acid HCl salt (see Working Example 4-3) (182 mg, 0.612 mmol) was added thionyl chloride (2 mL), and this was stirred at reflux for 3 hours. After the reaction was complete, concentration at reduced pressure gave a residue that was added to 2-amino-4-ethylphenol (106 mg, 0.612 mmol), triethylamine (309 mg, 3.06 mmol) and tetrahydrofuran (5 mL), and this was stirred at room temperature for 14 hours. After the reaction was complete, this was concentrated, and to a dioxane (5 mL) solution of the residue obtained was added methanesulfonic acid (353 mg, 1.46 mmol), and this was heated to reflux for 18 hours. After the reaction solution was cooled, water and saturated aqueous sodium hydrogen carbonate solution were added, and this was extracted with chloroform. After the organic layer obtained was dried over anhydrous sodium sulfate, it was filtered and concentrated. The residue obtained was purified by silica gel column chromatography to yield the title compound (40 mg, 18% yield) as pale yellow crystals. at reflux for 3 hours concentration at reduced pressure gave a residue that this was stirred at room temperature for 14 hours this was concentrated to a dioxane (5 mL) solution of the residue obtained this was heated to reflux for 18 hours After the reaction solution was cooled this was extracted with chloroform After the organic layer obtained was dried over anhydrous sodium sulfate, it was filtered concentrated The residue obtained was purified by silica gel column chromatography

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

Procedure: To a mixture of 2-amino-4-ethylphenol (0.89 g, 0.0065 mol) in tetrahydrofuran (80 mL) was added 4-bromophenyl isothiocyanate (1.4 g, 0.0065 mol) at room temperature. The mixture was stirred for 2 hours at room temperature. Anhydrous copper sulfate (6.2 g, 0.039 mol), triethylamine (0.9 mL, 0.0065 mol) and silica gel (11.7 g) were added to the reaction mixture. The mixture was stirred for 4 hours at room temperature. The solvent was removed under reduced pressure. The mixture was filtered through silica gel pad using 25% ethyl acetate/n-heptane as a mobile phase to give brown colored solid. The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase. The solvent was removed, and the residue was triturated with n-heptane to give N2-(4-bromophenyl)-5-ethyl-1,3-benzoxazol-2-amine (0.96 g, 0.003 mol). RP-HPLC (Delta Pak C18, 5 μm, 300 A, 15 cm; 5%-95% acetonitrile-0.1M ammonium acetate over 10 min, 1 mL/min) Rt 12.1 min. MS: MH+: 318 The mixture was stirred for 4 hours at room temperature The solvent was removed under reduced pressure The mixture was filtered through silica gel pad to give brown colored solid The solid was purified by flash column chromatography on silica using 0%-25% ethyl acetate/n-heptane as a mobile phase The solvent was removed the residue was triturated with n-heptane