4-bromo-N'-hydroxybenzenecarboximidamide

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

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 stirred solution of ice cooled methanol (115 ml), under argon, was added potassium tert-butoxide (10.12 g. 0.09 mol), portionwise. After stirring for 5 minutes hydroxylamine hydrochloride (6.71 g, 0.097 mol) was added in one portion. After stirring for 1 hour at room temperature a slurry of 4-bromobenzonitrile, (10.88 g, 0.06 mol) in methanol (150 ml) was added. The mixture was then heated at reflux for 4 hours, cooled and filtered. The filtrate was evaporated in vacuo to give the title compound as a colourless solid (14.12 g, quant.) was added in one portion was added The mixture was then heated at reflux for 4 hours cooled filtered The filtrate was evaporated in vacuo

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

Procedure: To a solution of N-Boc-L-proline (2.5 g, 11.6 mmol) in N,N-dimethylformamide (18 mL), O-(Benzotriazol-1-yl)-N,N,N′,N′-tetra methyluronium tetrafluoroborate (TBTU, 3.73 g, 11.6 mmol), HOBt.H2O (0.36 g, 2.32 mmol) and DIPEA (10.2 ml, 58.1 mmol) were added. After the reaction mixture was stirred at room temperature for 5 minutes, 4-Bromo-N′-hydroxybenzimidamide 15 (2.5 g, 11.6 mmol) was added. The mixture was then stirred at 110° C. for 2.5 hours. After cooled to room temperature, the resulting mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered and concentrated to yield a crude yellow liquid, which was purified with chromatography (ethyl acetate: n-hexane=1:10) to give the desired product 16a (2.5 g). The mixture was then stirred at 110° C. for 2.5 hours After cooled to room temperature the resulting mixture was extracted with ethyl acetate dried over magnesium sulfate filtered concentrated to yield a crude yellow liquid, which was purified with chromatography (ethyl acetate: n-hexane=1:10)

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4-bromobenzonitrile (5.0 g, 27.5 mmol) in ethanol (42 ml) at room temperature, hydroxylamine hydrochloride (1.91 g, 27.5 mmol) and DIPEA (4.8 ml, 27.5 mmol) were added. The reaction mixture was stirred at 90° C. for 5 hours. After cooled to room temperature, the resulting mixture was concentrated to yield a colorless viscous liquid. The liquid was extracted with ethyl acetate and the organic layer was dried over magnesium sulfate, filtered and then concentrated to give a crude compound, which was washed with n-hexane to yield product 15 as a white solid (5.0 g). After cooled to room temperature the resulting mixture was concentrated to yield a colorless viscous liquid The liquid was extracted with ethyl acetate the organic layer was dried over magnesium sulfate filtered concentrated to give a crude compound, which was washed with n-hexane

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

Procedure: in good yield. In contrast, under N-coupling conditions the benzamidoxime was converted to benzonitrile (Anbazhagan et al., (2002) Tetrahedron Lett. 43: 4221) and attempted Heck coupling of 4-bromobenzamidoxime with 2(4-cyanophenyl)furan yielded 2,5-bis(4-cyanophenyl)furan.

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

Procedure: To a stirred solution of ice cooled methanol (115 ml), under argon, was added potassium tert-butoxide (10.12 g. 0.09 mol), portionwise. After stirring for 5 minutes hydroxylamine hydrochloride (6.71 g, 0.097 mol) was added in one portion. After stirring for 1 hour at room temperature a slurry of 4-bromobenzonitrile, (10.88 g, 0.06 mol) in methanol (150 ml) was added. The mixture was then heated at reflux for 4 hours, cooled and filtered. The filtrate was evaporated in vacuo to give the title compound as a colourless solid (14.12 g, quant.) was added in one portion was added The mixture was then heated at reflux for 4 hours cooled filtered The filtrate was evaporated in vacuo