tert-butyl N-(cyclobutylideneamino)carbamate

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: A reaction mixture of cyclobutanone (7.01 g, 100 mmol) and tert-butyl hydrazinecarboxylate (13.22 g, 100 mmol) in hexane (100 mL) was heated under reflux for 2 hours. After cooling down, a precipitate was formed and collected. It was then triturated with isopropanol (5 mL) and hexane (50 mL) to give a white solid as final product tert-butyl 2-cyclobutylidenehydrazinecarboxylate (13.5 g, 73.3 mmol, 73.3% yield). 1H NMR (500 MHz, CHLOROFORM-D) δ ppm 1.50 (s, 9H) 1.96-2.08 (m, 2H) 2.75-2.84 (m, 2H) 2.93-3.05 (m, 2H). MS m/z 207 (M+Na+), Retention time: 1.420 min. (acid). was heated under reflux for 2 hours After cooling down a precipitate was formed collected It was then triturated with isopropanol (5 mL) and hexane (50 mL)

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

Procedure: A reaction mixture of cyclobutanone (7.01 g, 100 mmol) and tert-butyl hydrazinecarboxylate (13.22 g, 100 mmol) in hexane (100 mL) was heated under reflux for 2 hours. After cooling down, a precipitate was formed and collected. It was then triturated with isopropanol (5 mL) and hexane (50 mL) to give a white solid as final product tert-butyl 2-cyclobutylidenehydrazinecarboxylate (13.5 g, 73.3 mmol, 73.3% yield). 1H NMR (500 MHz, CHLOROFORM-D) δ ppm 1.50 (s, 9H) 1.96-2.08 (m, 2H) 2.75-2.84 (m, 2H) 2.93-3.05 (m, 2H). MS m/z 207 (M+Na+), Retention time: 1.420 min. (acid). was heated under reflux for 2 hours After cooling down a precipitate was formed collected It was then triturated with isopropanol (5 mL) and hexane (50 mL)

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

Procedure: The reaction mixture of cyclobutanone (15 g, 214 mmol) and hydrazinecarboxylic acid tert-butyl ester (28.3 g, 214 mmol) in hexane (225 mL) was heated to reflux for 2 hours. After cooling down, a precipitate formed and the solid was filtered under vacuum. Isopropanol (10 mL) and hexane (100 mL) were added to the solid and the mixture was put on the rotary evaporator under vacuum until a slurry was generated. After filtration, the solid was washed with hexane twice and dried in vacuo to afford N′-cyclobutylidene-hydrazinecarboxylic acid tert-butyl ester (32 g, 81%) as white solid which was used without further purification. was heated to reflux for 2 hours After cooling down a precipitate formed the solid was filtered under vacuum Isopropanol (10 mL) and hexane (100 mL) were added to the solid the mixture was put on the rotary evaporator under vacuum until a slurry After filtration the solid was washed with hexane twice dried in vacuo

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: The reaction mixture of cyclobutanone (15 g, 214 mmol) and hydrazinecarboxylic acid tert-butyl ester (28.3 g, 214 mmol) in hexane (225 mL) was heated to reflux for 2 hours. After cooling down, a precipitate formed and the solid was filtered under vacuum. Isopropanol (10 mL) and hexane (100 mL) were added to the solid and the mixture was put on the rotary evaporator under vacuum until a slurry was generated. After filtration, the solid was washed with hexane twice and dried in vacuo to afford N′-cyclobutylidene-hydrazinecarboxylic acid tert-butyl ester (32 g, 81%) as white solid which was used without further purification. was heated to reflux for 2 hours After cooling down a precipitate formed the solid was filtered under vacuum Isopropanol (10 mL) and hexane (100 mL) were added to the solid the mixture was put on the rotary evaporator under vacuum until a slurry After filtration the solid was washed with hexane twice dried in vacuo

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

Procedure: A solution of tert-butyl 2-cyclobutylidenehydrazinecarboxylate (5.0 g, 27.1 mmol) in THF (50 mL) was added dropwise over 1.5 hours to a solution of borane tetrahydrofuran complex (33.9 mL, 33.9 mmol) under a nitrogen atmosphere. The reaction mixture was stirred at room temperature for 2.5 hours. Borane tetrahydrofuran (3 mL, 3 mmol) was added dropwise and the mixture was stirred at room temperature overnight. The resulting mixture was quenched cautiously by the addition of water (50 mL) and the mixture was concentrated under reduced pressure. The residue was diluted with water (30 mL) and extracted with EtOAc (2×200 mL), using brine to aid the separation. The combined organic extracts were washed with brine, dried over MgSO4, filtered and the solvent was removed under reduced pressure. The crude material was adsorbed onto silica and purification by chromatography eluting with 0-10% EtOAc in iso-hexane afforded the title compound. the mixture was stirred at room temperature overnight The resulting mixture was quenched cautiously by the addition of water (50 mL) the mixture was concentrated under reduced pressure The residue was diluted with water (30 mL) extracted with EtOAc (2×200 mL) the separation The combined organic extracts were washed with brine dried over MgSO4 filtered the solvent was removed under reduced pressure The crude material was adsorbed onto silica and purification by chromatography eluting with 0-10% EtOAc in iso-hexane

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

Procedure: A mixture of cyclobutanone (16.96 ml, 227 mmol) and tert-butyl hydrazinecarboxylate (30 g, 227 mmol) in isohexane (378 mL), under nitrogen was stirred at reflux for 1 hour. The reaction mixture was cooled to room temperature and stirred for 1 hour. The resulting suspension was filtered, rinsing the solid with iso-hexane (×2). The solid was dried under vacuum at 30° C. to afford the title compound; at reflux for 1 hour stirred for 1 hour The resulting suspension was filtered rinsing the solid with iso-hexane (×2) The solid was dried under vacuum at 30° C.

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

Procedure: A reaction mixture of cyclobutanone (7.01 g, 100 mmol) and tert-butyl hydrazinecarboxylate (13.22 g, 100 mmol) in hexane (100 mL) was heated under reflux for 2 hours. After cooling down, a precipitate was formed and collected. It was then triturated with isopropanol (5 mL) and hexane (50 mL) to give a white solid as final product tert-butyl 2-cyclobutylidenehydrazinecarboxylate (13.5 g, 73.3 mmol, 73.3% yield). 1H NMR (500 MHz, CHLOROFORM-D) δ ppm 1.50 (s, 9H) 1.96-2.08 (m, 2H) 2.75-2.84 (m, 2H) 2.93-3.05 (m, 2H). MS m/z 207 (M+Na+), Retention time: 1.420 min. (acid). was heated under reflux for 2 hours After cooling down a precipitate was formed collected It was then triturated with isopropanol (5 mL) and hexane (50 mL)

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

Procedure: The reaction mixture of cyclobutanone (15 g, 214 mmol) and hydrazinecarboxylic acid tert-butyl ester (28.3 g, 214 mmol) in hexane (225 mL) was heated to reflux for 2 hours. After cooling down, a precipitate formed and the solid was filtered under vacuum. Isopropanol (10 mL) and hexane (100 mL) were added to the solid and the mixture was put on the rotary evaporator under vacuum until a slurry was generated. After filtration, the solid was washed with hexane twice and dried in vacuo to afford N′-cyclobutylidene-hydrazinecarboxylic acid tert-butyl ester (32 g, 81%) as white solid which was used without further purification. was heated to reflux for 2 hours After cooling down a precipitate formed the solid was filtered under vacuum Isopropanol (10 mL) and hexane (100 mL) were added to the solid the mixture was put on the rotary evaporator under vacuum until a slurry After filtration the solid was washed with hexane twice dried in vacuo