3-Hydroxy-cyclobutanecarboxylic acid ethyl ester

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

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

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

Procedure: To a solution of 1-(biphenyl-4-ylmethyl)-4,6-difluoro-5-iodo-2-(methylsulfonyl)-1H-benzimidazole (Intermediate 5, 0.457 g, 0.872 mmol) and 3-hydroxy-cyclobutanecarboxylic acid ethyl ester (Intermediate 12, 0.503 g, 3.49 mmol) in 2.9 mL of DMF was added DBU (0.526 mL, 3.49 mmol) dropwise via syringe. The reaction was heated at 80° C. for 1 h, and then diluted with EtOAc and H2O. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated. The resulting crude residue was purified on silica gel (eluted 2-15% then 15% then 15-20% EtOAc/hexanes: gradient elution) to give the desired product. LCMS: calculated for C27H23F2IN2O3 588.38, observed m/e 588.9 (M+H)+ (Rt 2.55/4 min). The layers were separated the aqueous layer was extracted with EtOAc The combined organic layers were washed with brine dried over Na2SO4 filtered concentrated The resulting crude residue was purified on silica gel ( eluted 2-15% 15% then 15-20% EtOAc/hexanes: gradient elution)

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

Procedure: To a solution of ethyl 3-hydroxycyclobutanecarboxylate (10.2 g, 78.4 mmol) in dry pyridine (56.5 mL) at 0° C., TsCl (14.9 g, 78.4 mml) was added portion-wise. The resulting mixture was stirred at rt overnight. The reaction mixture was concentrated in vacuo and the residue obtained was dissolved in EtOAc (100 mL) and sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL). The organic layer was dried over Na2SO4, filtered, and concentrated to obtain ethyl 3-(tosyloxy)cyclobutanecarboxylate as a pale yellow oil, which was used in the next step without further purification. The reaction mixture was concentrated in vacuo the residue obtained sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL) The organic layer was dried over Na2SO4 filtered concentrated

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

Procedure: To a solution of 1-(biphenyl-4-ylmethyl)-4,6-difluoro-5-iodo-2-(methylsulfonyl)-1H-benzimidazole (Intermediate 5, 0.457 g, 0.872 mmol) and 3-hydroxy-cyclobutanecarboxylic acid ethyl ester (Intermediate 12, 0.503 g, 3.49 mmol) in 2.9 mL of DMF was added DBU (0.526 mL, 3.49 mmol) dropwise via syringe. The reaction was heated at 80° C. for 1 h, and then diluted with EtOAc and H2O. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated. The resulting crude residue was purified on silica gel (eluted 2-15% then 15% then 15-20% EtOAc/hexanes: gradient elution) to give the desired product. LCMS: calculated for C27H23F2IN2O3 588.38, observed m/e 588.9 (M+H)+ (Rt 2.55/4 min). The layers were separated the aqueous layer was extracted with EtOAc The combined organic layers were washed with brine dried over Na2SO4 filtered concentrated The resulting crude residue was purified on silica gel ( eluted 2-15% 15% then 15-20% EtOAc/hexanes: gradient elution)

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

Procedure: To a solution of 1-(biphenyl-4-ylmethyl)-4,6-difluoro-5-iodo-2-(methylsulfonyl)-1H-benzimidazole (Intermediate 5, 0.457 g, 0.872 mmol) and 3-hydroxy-cyclobutanecarboxylic acid ethyl ester (Intermediate 12, 0.503 g, 3.49 mmol) in 2.9 mL of DMF was added DBU (0.526 mL, 3.49 mmol) dropwise via syringe. The reaction was heated at 80° C. for 1 h, and then diluted with EtOAc and H2O. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated. The resulting crude residue was purified on silica gel (eluted 2-15% then 15% then 15-20% EtOAc/hexanes: gradient elution) to give the desired product. LCMS: calculated for C27H23F2IN2O3 588.38, observed m/e 588.9 (M+H)+ (Rt 2.55/4 min). The layers were separated the aqueous layer was extracted with EtOAc The combined organic layers were washed with brine dried over Na2SO4 filtered concentrated The resulting crude residue was purified on silica gel ( eluted 2-15% 15% then 15-20% EtOAc/hexanes: gradient elution)

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

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

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

Procedure: To a solution of ethyl 3-hydroxycyclobutanecarboxylate (10.2 g, 78.4 mmol) in dry pyridine (56.5 mL) at 0° C., TsCl (14.9 g, 78.4 mmol) was added portionwise. The resulting mixture was stirred at rt overnight. The reaction mixture was concentrated under reduced pressure and the residue obtained was dissolved in EtOAc (100 mL) and sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL). The EtOAc layer was dried over Na2SO4, filtered, and concentrated to obtain ethyl 3-(tosyloxy)cyclobutanecarboxylate as a pale yellow oil, which was used in the next step without further purification. The reaction mixture was concentrated under reduced pressure the residue obtained sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL) The EtOAc layer was dried over Na2SO4 filtered concentrated

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

Procedure: To a solution of ethyl 3-hydroxycyclobutanecarboxylate (10.2 g, 78.4 mmol) in dry pyridine (56.5 mL) at 0° C., TsCl (14.9 g, 78.4 mml) was added portion-wise. The resulting mixture was stirred at rt overnight. The reaction mixture was concentrated in vacuo and the residue obtained was dissolved in EtOAc (100 mL) and sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL). The organic layer was dried over Na2SO4, filtered, and concentrated to obtain ethyl 3-(tosyloxy)cyclobutanecarboxylate as a pale yellow oil, which was used in the next step without further purification. The reaction mixture was concentrated in vacuo the residue obtained sequentially washed with 2 N HCl (100 mL), saturated NaHCO3 (100 mL) and water (100 mL) The organic layer was dried over Na2SO4 filtered concentrated

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

Procedure: To a solution of 1-(biphenyl-4-ylmethyl)-4,6-difluoro-5-iodo-2-(methylsulfonyl)-1H-benzimidazole (Intermediate 5, 0.457 g, 0.872 mmol) and 3-hydroxy-cyclobutanecarboxylic acid ethyl ester (Intermediate 12, 0.503 g, 3.49 mmol) in 2.9 mL of DMF was added DBU (0.526 mL, 3.49 mmol) dropwise via syringe. The reaction was heated at 80° C. for 1 h, and then diluted with EtOAc and H2O. The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated. The resulting crude residue was purified on silica gel (eluted 2-15% then 15% then 15-20% EtOAc/hexanes: gradient elution) to give the desired product. LCMS: calculated for C27H23F2IN2O3 588.38, observed m/e 588.9 (M+H)+ (Rt 2.55/4 min). The layers were separated the aqueous layer was extracted with EtOAc The combined organic layers were washed with brine dried over Na2SO4 filtered concentrated The resulting crude residue was purified on silica gel ( eluted 2-15% 15% then 15-20% EtOAc/hexanes: gradient elution)