diethyl 2,2-bis(trifluoromethylsulfonyloxymethyl)propanedioate

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

Procedure: To a solution of (R)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 49 (247 mg, 0.62 mmol) in CH3CN (2 mL) at −10° C., under N2, was added diethyl 2,2-bis((((trifluoromethyl)sulfonyl)oxy)methyl)malonate INT-26 (3 mL of 0.25 mmol solution in CH3CN). The resulting mixture was warmed to room temperature over 30 min, then heated to 70° C. for 18 h. The mixture was concentrated, dissolved in DCM, and washed with water. The organic layer was dried over Na2SO4 and concentrated to provide 93 mg (28%) of crude (R)-diethyl 1-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)azetidine-3,3-dicarboxylate INT-27, which was used in the next step without further purification. LCMS-ESI (m/z) calculated for C30H32N4O6: 544.6. found 545.2 [M+H]+, tR=3.03 min. heated to 70° C. for 18 h The mixture was concentrated dissolved in DCM washed with water The organic layer was dried over Na2SO4 concentrated

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

Procedure: To a solution of (R)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 49 (247 mg, 0.62 mmol) in CH3CN (2 mL) at −10° C., under N2, was added diethyl 2,2-bis((((trifluoromethyl)sulfonyl)oxy)methyl)malonate INT-26 (3 mL of 0.25 mmol solution in CH3CN). The resulting mixture was warmed to room temperature over 30 min, then heated to 70° C. for 18 h. The mixture was concentrated, dissolved in DCM, and washed with water. The organic layer was dried over Na2SO4 and concentrated to provide 93 mg (28%) of crude (R)-diethyl 1-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)azetidine-3,3-dicarboxylate INT-27, which was used in the next step without further purification. LCMS-ESI (m/z) calculated for C30H32N4O6: 544.6. found 545.2 [M+H]+, tR=3.03 min. heated to 70° C. for 18 h The mixture was concentrated dissolved in DCM washed with water The organic layer was dried over Na2SO4 concentrated

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

Procedure: To a solution of (R)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 49 (247 mg, 0.62 mmol) in CH3CN (2 mL) at −10° C., under N2, was added diethyl 2,2-bis((((trifluoromethyl)sulfonyl)oxy)methyl)malonate INT-26 (3 mL of 0.25 mmol solution in CH3CN). The resulting mixture was warmed to room temperature over 30 min, then heated to 70° C. for 18 h. The mixture was concentrated, dissolved in DCM, and washed with water. The organic layer was dried over Na2SO4 and concentrated to provide 93 mg (28%) of crude (R)-diethyl 1-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)azetidine-3,3-dicarboxylate INT-27, which was used in the next step without further purification. LCMS-ESI (m/z) calculated for C30H32N4O6: 544.6; found 545.2 [M+H]+, tR=3.03 min. heated to 70° C. for 18 h The mixture was concentrated dissolved in DCM washed with water The organic layer was dried over Na2SO4 concentrated

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

Procedure: To a solution of (R)-5-(3-(1-amino-2,3-dihydro-1H-inden-4-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 49 (247 mg, 0.62 mmol) in CH3CN (2 mL) at −10° C., under N2, was added diethyl 2,2-bis((((trifluoromethyl)sulfonyl)oxy)methyl)malonate INT-26 (3 mL of 0.25 mmol solution in CH3CN). The resulting mixture was warmed to room temperature over 30 min, then heated to 70° C. for 18 h. The mixture was concentrated, dissolved in DCM, and washed with water. The organic layer was dried over Na2SO4 and concentrated to provide 93 mg (28%) of crude (R)-diethyl 1-(4-(5-(3-cyano-4-isopropoxyphenyl)-1,2,4-oxadiazol-3-yl)-2,3-dihydro-1H-inden-1-yl)azetidine-3,3-dicarboxylate INT-27, which was used in the next step without further purification. LCMS-ESI (m/z) calculated for C30H32N4O6: 544.6. found 545.2 [M+H]+, tR=3.03 min. heated to 70° C. for 18 h The mixture was concentrated dissolved in DCM washed with water The organic layer was dried over Na2SO4 concentrated