4-bromo-2-fluoro-1-isocyanatobenzene

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

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

Procedure: In a round bottom flask under nitrogen, a solution of 1,1-dimethylethyl 3-(2-hydrazino-2-oxoethyl)-1-azetidinecarboxylate (15.18 mmol) in dichloromethane (20 mL) at 0° C. was treated with 4-bromo-2-fluorophenylisocyanate (15.18 mmol). The cooling bath was removed and the clear yellow solution was stirred at room temperature for 1 h. The reaction mixture was concentrated in vacuo to afford the crude title compound as a white foamy solid. This material was used directly without further purification. MS(ES)+ m/e 445.2, 447.2 [M+H]+. The cooling bath was removed The reaction mixture was concentrated in vacuo

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

Procedure: A solution of 1,1-dimethylethyl (3S)-3-(2-hydrazino-2-oxoethyl)-1-pyrrolidinecarboxylate (6.58 mmol) in dichloromethane (15 mL) was cooled to 0° C. and was treated drop-wise with 4-bromo-2-fluoro-1-isocyanatobenzene (6.58 mmol). The reaction was allowed to warm to room temperature, and after ˜30 min a white solid had formed. The reaction contents were concentrated to dryness in vacuo. No further purification was carried out on the resulting white solid (3.01 grams, 100%). MS(ES)+ m/e 459/461 [M+H]+ (bromide isotope pattern). after ˜30 min a white solid had formed The reaction contents were concentrated to dryness in vacuo No further purification

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

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

Procedure: In a round bottom flask under nitrogen, a solution of 1,1-dimethylethyl 3-(2-hydrazino-2-oxoethyl)-1-azetidinecarboxylate (15.18 mmol) in dichloromethane (20 mL) at 0° C. was treated with 4-bromo-2-fluorophenylisocyanate (15.18 mmol). The cooling bath was removed and the clear yellow solution was stirred at room temperature for 1 h. The reaction mixture was concentrated in vacuo to afford the crude title compound as a white foamy solid. This material was used directly without further purification. MS(ES)+ m/e 445.2, 447.2 [M+H]+. The cooling bath was removed The reaction mixture was concentrated in vacuo

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

Procedure: A solution of 1,1-dimethylethyl (3S)-3-(2-hydrazino-2-oxoethyl)-1-pyrrolidinecarboxylate (6.58 mmol) in dichloromethane (15 mL) was cooled to 0° C. and was treated drop-wise with 4-bromo-2-fluoro-1-isocyanatobenzene (6.58 mmol). The reaction was allowed to warm to room temperature, and after ˜30 min a white solid had formed. The reaction contents were concentrated to dryness in vacuo. No further purification was carried out on the resulting white solid (3.01 grams, 100%). MS(ES)+ m/e 459/461 [M+H]+ (bromide isotope pattern). after ˜30 min a white solid had formed The reaction contents were concentrated to dryness in vacuo No further purification

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

Procedure: A solution of 1,1-dimethylethyl (3S)-3-(2-hydrazino-2-oxoethyl)-1-pyrrolidinecarboxylate (6.58 mmol) in dichloromethane (15 mL) was cooled to 0° C. and was treated drop-wise with 4-bromo-2-fluoro-1-isocyanatobenzene (6.58 mmol). The reaction was allowed to warm to room temperature, and after ˜30 min a white solid had formed. The reaction contents were concentrated to dryness in vacuo. No further purification was carried out on the resulting white solid (3.01 grams, 100%). MS(ES)+ m/e 459/461 [M+H]+ (bromide isotope pattern). after ˜30 min a white solid had formed The reaction contents were concentrated to dryness in vacuo No further purification

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

Procedure: In a round bottom flask under nitrogen, a solution of 1,1-dimethylethyl 3-(2-hydrazino-2-oxoethyl)-1-azetidinecarboxylate (15.18 mmol) in dichloromethane (20 mL) at 0° C. was treated with 4-bromo-2-fluorophenylisocyanate (15.18 mmol). The cooling bath was removed and the clear yellow solution was stirred at room temperature for 1 h. The reaction mixture was concentrated in vacuo to afford the crude title compound as a white foamy solid. This material was used directly without further purification. MS(ES)+ m/e 445.2, 447.2 [M+H]+. The cooling bath was removed The reaction mixture was concentrated in vacuo

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

Procedure: A solution of 1,1-dimethylethyl (3S)-3-(2-hydrazino-2-oxoethyl)-1-pyrrolidinecarboxylate (6.58 mmol) in dichloromethane (15 mL) was cooled to 0° C. and was treated drop-wise with 4-bromo-2-fluoro-1-isocyanatobenzene (6.58 mmol). The reaction was allowed to warm to room temperature, and after ˜30 min a white solid had formed. The reaction contents were concentrated to dryness in vacuo. No further purification was carried out on the resulting white solid (3.01 grams, 100%). MS(ES)+ m/e 459/461 [M+H]+ (bromide isotope pattern). after ˜30 min a white solid had formed The reaction contents were concentrated to dryness in vacuo No further purification

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