1,1-dimethylhydrazine;hydrochloride

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

Procedure: To a solution of 1-(2-chloro-5-nitrophenyl)ethanone (500 mg, 2.5 mmol) in anhydrous ethanol (15 mL) was added 1,1-dimethylhydrazine hydrochloride (3.38 g, 35.0 mmol) under nitrogen protection. The mixture was heated at reflux for 10 h and evaporated under reduced pressure to afford crude 307a (3.0 g), which was used in the next step without further purification. MS-ESI: [M+H]+ 192.2 The mixture was heated at reflux for 10 h evaporated under reduced pressure

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

Procedure: To a solution of 1-(2-chloro-5-nitrophenyl)ethanone (500 mg, 2.5 mmol) in anhydrous ethanol (15 mL) was added 1,1-dimethylhydrazine hydrochloride (3.38 g, 35.0 mmol) under nitrogen protection. The mixture was heated at reflux for 10 h and evaporated under reduced pressure to afford crude 307a (3.0 g), which was used in the next step without further purification. MS-ESI: [M+H]+ 192.2 The mixture was heated at reflux for 10 h evaporated under reduced pressure

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of diethyl but-2-ynedioate (100 g, 0.588 mol) in a mixture of EtOH (600 mL) and water (600 mL) was added a solution of 1,1-dimethylhydrazine hydrochloride (68 g, 0.705 mol) and NaOH (28.2 g, 0.705 mol) in water (150 mL) dropwise at 0° C. over a period of 20 min. The mixture was stirred at 0° C. for 30 min and 20° C. for 60 min. To the reaction mixture was added EtOAc (800 mL) and stirred. The mixture was separated and the aqueous layer was concentrated. The residue was dissolved in 1N HCl (1 L) and stirred at rt for 90 min. CH2Cl2 (500 mL) was added and the mixture stirred, separated and the aqueous layer was concentrated. The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1) to give the title compound (17 g, 17% yield) as a white solid. stirred The mixture was separated the aqueous layer was concentrated The residue was dissolved in 1N HCl (1 L) stirred at rt for 90 min CH2Cl2 (500 mL) was added the mixture stirred separated the aqueous layer was concentrated The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1)

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of diethyl but-2-ynedioate (100 g, 0.588 mol) in a mixture of EtOH (600 mL) and water (600 mL) was added a solution of 1,1-dimethylhydrazine hydrochloride (68 g, 0.705 mol) and NaOH (28.2 g, 0.705 mol) in water (150 mL) dropwise at 0° C. over a period of 20 min. The mixture was stirred at 0° C. for 30 min and 20° C. for 60 min. To the reaction mixture was added EtOAc (800 mL) and stirred. The mixture was separated and the aqueous layer was concentrated. The residue was dissolved in 1N HCl (1 L) and stirred at rt for 90 min. CH2Cl2 (500 mL) was added and the mixture stirred, separated and the aqueous layer was concentrated. The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1) to give the title compound (17 g, 17% yield) as a white solid. stirred The mixture was separated the aqueous layer was concentrated The residue was dissolved in 1N HCl (1 L) stirred at rt for 90 min CH2Cl2 (500 mL) was added the mixture stirred separated the aqueous layer was concentrated The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1)

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

Procedure: To a solution of 1-(2-chloro-5-nitrophenyl)ethanone (500 mg, 2.5 mmol) in anhydrous ethanol (15 mL) was added 1,1-dimethylhydrazine hydrochloride (3.38 g, 35.0 mmol) under nitrogen protection. The mixture was heated at reflux for 10 h and evaporated under reduced pressure to afford crude 307a (3.0 g), which was used in the next step without further purification. MS-ESI: [M+H] 192.2 The mixture was heated at reflux for 10 h evaporated under reduced pressure

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

Procedure: To a solution of 1-(2-chloro-5-nitrophenyl)ethanone (500 mg, 2.5 mmol) in anhydrous ethanol (15 mL) was added 1,1-dimethylhydrazine hydrochloride (3.38 g, 35.0 mmol) under nitrogen protection. The mixture was heated at reflux for 10 h and evaporated under reduced pressure to afford crude 307a (3.0 g), which was used in the next step without further purification. MS-ESI: [M+H]+ 192.2 The mixture was heated at reflux for 10 h evaporated under reduced pressure

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

Procedure: To a solution of 1-(2-chloro-5-nitrophenyl)ethanone (500 mg, 2.5 mmol) in anhydrous ethanol (15 mL) was added 1,1-dimethylhydrazine hydrochloride (3.38 g, 35.0 mmol) under nitrogen protection. The mixture was heated at reflux for 10 h and evaporated under reduced pressure to afford crude 307a (3.0 g), which was used in the next step without further purification. MS-ESI: [M+H]+ 192.2 The mixture was heated at reflux for 10 h evaporated under reduced pressure

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of diethyl but-2-ynedioate (100 g, 0.588 mol) in a mixture of EtOH (600 mL) and water (600 mL) was added a solution of 1,1-dimethylhydrazine hydrochloride (68 g, 0.705 mol) and NaOH (28.2 g, 0.705 mol) in water (150 mL) dropwise at 0° C. over a period of 20 min. The mixture was stirred at 0° C. for 30 min and 20° C. for 60 min. To the reaction mixture was added EtOAc (800 mL) and stirred. The mixture was separated and the aqueous layer was concentrated. The residue was dissolved in 1N HCl (1 L) and stirred at rt for 90 min. CH2Cl2 (500 mL) was added and the mixture stirred, separated and the aqueous layer was concentrated. The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1) to give the title compound (17 g, 17% yield) as a white solid. stirred The mixture was separated the aqueous layer was concentrated The residue was dissolved in 1N HCl (1 L) stirred at rt for 90 min CH2Cl2 (500 mL) was added the mixture stirred separated the aqueous layer was concentrated The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1)