ethyl N-phenylmethanimidate

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

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

Procedure: Five grams of 4-(4-aminophenyl)-1-H-imidazole were added to a solution of 4.6 gm of ethyl N-phenyl-formimidate [Org. Synth., 35, 65 (1965)] in 25 ml of acetone. After stirring for four hours at room temperature, the solid that separated was filtered and dried under vacuum. The product was treated with acetone and acidified with glacial acetic acid. N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered to give 4.6 gm of the desired product. the solid that separated was filtered dried under vacuum The product was treated with acetone N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered

Conditions: temp:175.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A round bottomed flask containing a mixture of 5-hydroxy-1H-indazole (28.5 g) and ethyl N—phenylformimidate (35 g) was submerged rapidly in an oil bath pre-heated to 175° C. and the mixture stirred at 160-180° C. for 30 minutes, the ethanol produced in the reaction being removed by distillation. The cooled mixture was then treated with boiling methanol (500 ml) and the resultant brown solid collected by filtration, washed with methanol (100 ml) and dried to give 5-hydroxy-4-(N-phenyliminomethyl)-1H-indazole (32 g) as a yellow solid. The solid was dissolved in hydrochloric acid (5 M; 500 ml) and heated at 50-60° C. with stirring for 2 hours. The mixture was diluted with water (500 ml) and extracted with ethyl acetate (2×500 ml). The combined extracts were washed with water (500 ml), dried over magnesium sulphate and the solvent evaporated under reduced pressure to give 5-hydroxy-1H-indazole-4-carboxaldehyde (15.48 g) as a yellow solid. A round bottomed flask containing was submerged rapidly in an oil bath being removed by distillation The cooled mixture was then treated with boiling methanol (500 ml) the resultant brown solid collected by filtration washed with methanol (100 ml) dried

Conditions: temp:175.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A round bottomed flask containing a mixture of 5-hydroxy-1H-indazole (28.5 g) and ethyl N—phenylformimidate (35 g) was submerged rapidly in an oil bath pre-heated to 175° C. and the mixture stirred at 160-180° C. for 30 minutes, the ethanol produced in the reaction being removed by distillation. The cooled mixture was then treated with boiling methanol (500 ml) and the resultant brown solid collected by filtration, washed with methanol (100 ml) and dried to give 5-hydroxy-4-(N-phenyliminomethyl)-1H-indazole (32 g) as a yellow solid. The solid was dissolved in hydrochloric acid (5 M; 500 ml) and heated at 50-60° C. with stirring for 2 hours. The mixture was diluted with water (500 ml) and extracted with ethyl acetate (2×500 ml). The combined extracts were washed with water (500 ml), dried over magnesium sulphate and the solvent evaporated under reduced pressure to give 5-hydroxy-1H-indazole-4-carboxaldehyde (15.48 g) as a yellow solid. A round bottomed flask containing was submerged rapidly in an oil bath being removed by distillation The cooled mixture was then treated with boiling methanol (500 ml) the resultant brown solid collected by filtration washed with methanol (100 ml) dried

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

Procedure: The synthesis is achieved in three steps. The first step is the preparation of N,N′-diphenyl formamidine (by the reaction of aniline with triethyl orthoformate). This intermediate is then further reacted with triethyl orthoformate to produce ethyl N-phenylimidoformate. The final step is the reaction of ethyl phenylimidoformate with 4-aminostyrene to give the product.

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

Procedure: Five grams of 4-(4-aminophenyl)-1-H-imidazole were added to a solution of 4.6 gm of ethyl N-phenyl-formimidate [Org. Synth., 35, 65 (1965)] in 25 ml of acetone. After stirring for four hours at room temperature, the solid that separated was filtered and dried under vacuum. The product was treated with acetone and acidified with glacial acetic acid. N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered to give 4.6 gm of the desired product. the solid that separated was filtered dried under vacuum The product was treated with acetone N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered

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

Procedure: Five grams of 4-(4-aminophenyl)-1-H-imidazole were added to a solution of 4.6 gm of ethyl N-phenyl-formimidate [Org. Synth., 35, 65 (1965)] in 25 ml of acetone. After stirring for four hours at room temperature, the solid that separated was filtered and dried under vacuum. The product was treated with acetone and acidified with glacial acetic acid. N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered to give 4.6 gm of the desired product. the solid that separated was filtered dried under vacuum The product was treated with acetone N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered

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

Procedure: Five grams of 4-(4-aminophenyl)-1-H-imidazole were added to a solution of 4.6 gm of ethyl N-phenyl-formimidate [Org. Synth., 35, 65 (1965)] in 25 ml of acetone. After stirring for four hours at room temperature, the solid that separated was filtered and dried under vacuum. The product was treated with acetone and acidified with glacial acetic acid. N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered to give 4.6 gm of the desired product. the solid that separated was filtered dried under vacuum The product was treated with acetone N-Phenyl-N'-[4-(imidazol-4-yl]-formamidine crystallized as acetate salt which was filtered

Conditions: temp:175.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A round bottomed flask containing a mixture of 5-hydroxy-1H-indazole (28.5 g) and ethyl N—phenylformimidate (35 g) was submerged rapidly in an oil bath pre-heated to 175° C. and the mixture stirred at 160-180° C. for 30 minutes, the ethanol produced in the reaction being removed by distillation. The cooled mixture was then treated with boiling methanol (500 ml) and the resultant brown solid collected by filtration, washed with methanol (100 ml) and dried to give 5-hydroxy-4-(N-phenyliminomethyl)-1H-indazole (32 g) as a yellow solid. The solid was dissolved in hydrochloric acid (5 M; 500 ml) and heated at 50-60° C. with stirring for 2 hours. The mixture was diluted with water (500 ml) and extracted with ethyl acetate (2×500 ml). The combined extracts were washed with water (500 ml), dried over magnesium sulphate and the solvent evaporated under reduced pressure to give 5-hydroxy-1H-indazole-4-carboxaldehyde (15.48 g) as a yellow solid. A round bottomed flask containing was submerged rapidly in an oil bath being removed by distillation The cooled mixture was then treated with boiling methanol (500 ml) the resultant brown solid collected by filtration washed with methanol (100 ml) dried

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

Conditions: temp:150.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A slurry of 30 g (0.062 mole) of the 5,6-dichloro-1-ethyl-2-methyl-3-(2,2,2-trifluoroethyl)benzimidazolium p-toluenesulfonate in 150 mL of N,N-dimethylacetamide was treated with 45 g (about 0.3 mole, a large excess) of ethyl iso-formanilide, i.e., N-(ethoxymethylene)aniline, the mixture stirred and heated to 150° C., allowed to cool to 120° C. where it was maintained for 5 minutes, and then allowed to cool slowly to 30° C. The solution was poured into 1.5 L of cyclohexane, stirred, allowed to settle, and the dark reddish oil was separated. The oil was washed with another 500 mL of cyclohexane, separated, treated with 200 mL of methyl ethyl ketone, warmed to a uniform solution and cooled in a freezer to produce a bright yellow-orange solid. The solid was collected by filtration, washed with cold methy ethyl ketone, and dried to produce 23 g melting at 215°-217° C. The mass spec. and NMR spec. are consistent with the assigned structure. to cool to 120° C. where it was maintained for 5 minutes to cool slowly to 30° C the dark reddish oil was separated The oil was washed with another 500 mL of cyclohexane separated treated with 200 mL of methyl ethyl ketone warmed to a uniform solution cooled in a freezer to produce a bright yellow-orange solid The solid was collected by filtration washed with cold methy ethyl ketone dried to produce 23 g melting at 215°-217° C

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

Procedure: Thus, a mixture of triethyl orthoformate (1 equ.) and aniline (2 equ.) is heated at reflux for 2 hours. The ethanol evolved during the reaction is then distilled through a fractionating column. The reaction mixture is then allowed to cool, whereupon it solidifies. Recrystallisation of the solid from toluene yields N,N′-diphenyl formamidine in 80% yield. N,N′-diphenyl formamidine (1 equ.) and triethyl orthoformate (2 equ.) are mixed and a catalytic amount of dry aniline hydrochloride is then added. The mixture is heated and ethanol is seen to reflux within a few minutes. The mixture is heated at reflux for 1 hour and then the ethanol is distilled. Following the distillation, anhydrous potassium carbonate is added. The mixture is shaken and then allowed to stand for 2 hours. The reaction mixture is then distilled under reduced pressure. At 93 mmHg, excess triethyl orthoformate is collected at 83-85° C. The pressure is then reduced to 40 mmHg and ethyl N-phenylimdioformate is collected at 117° C. in 95% yield. is heated at reflux for 2 hours is then distilled through a fractionating column to cool, whereupon it Recrystallisation of the solid from toluene