3-methyl-4,5-dihydro-1H-pyrazole

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

Procedure: A solution of 100 g of 3-methyl-2-pyrazoline and 64 g of NaBr in 3,000 g of methanol was electrolysed with 2 F/mol of 3-methyl-2-pyrazoline at a current density of 6.8 A/dm2 at a temperature of 20° C. Customary working up of the electrolysed mixture and fractional distillation gave 24.5 g of 3-methyl-2-pyrazoline and 29.5 g of 3-methylpyrazole (boiling point 127°-131° C./98 mbar). This corresponds to a conversion of 75%, a yield of 30% and a selectivity of 40%. at a temperature of 20° C Customary working up of the electrolysed mixture and fractional distillation

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

Procedure: A solution of 100 g of 3-methyl-2-pyrazoline and 64 g of NaBr in 3,000 g of methanol was electrolysed with 2 F/mol of 3-methyl-2-pyrazoline at a current density of 6.8 A/dm2 at a temperature of 20° C. Customary working up of the electrolysed mixture and fractional distillation gave 24.5 g of 3-methyl-2-pyrazoline and 29.5 g of 3-methylpyrazole (boiling point 127°-131° C./98 mbar). This corresponds to a conversion of 75%, a yield of 30% and a selectivity of 40%. at a temperature of 20° C Customary working up of the electrolysed mixture and fractional distillation

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

Procedure: A solution of 100 g of 3-methyl-2-pyrazoline and 64 g of NaBr in 3,000 g of methanol was electrolysed with 2 F/mol of 3-methyl-2-pyrazoline at a current density of 6.8 A/dm2 at a temperature of 20° C. Customary working up of the electrolysed mixture and fractional distillation gave 24.5 g of 3-methyl-2-pyrazoline and 29.5 g of 3-methylpyrazole (boiling point 127°-131° C./98 mbar). This corresponds to a conversion of 75%, a yield of 30% and a selectivity of 40%. at a temperature of 20° C Customary working up of the electrolysed mixture and fractional distillation

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

Procedure: A mixture of 2.51 g of N-(2,6-difluorophenylsulphonyl)methylcarbamate, 1.68 g of 3-methyl-2-pyrazoline and 3 ml of pyridine in 20 ml of dioxane is heated on a steambath for 2 hours. After cooling the solvent is evaporated under reduced pressure and the residue is dissolved in 20 ml of water. This solution is filtrated and then acidified with conc. hydrochloric acid. The title compound, viz. 1-(2,6-difluorophenylsulphonylcarbamoyl)-3-methyl-2-pyrazoline, is obtained in a yield of 2.50 g; melting point 196° C. is heated on a steambath for 2 hours After cooling the solvent is evaporated under reduced pressure the residue is dissolved in 20 ml of water This solution is filtrated

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

Procedure: A solution of 100 g of 3-methyl-2-pyrazoline and 64 g of NaBr in 3,000 g of methanol was electrolysed with 2 F/mol of 3-methyl-2-pyrazoline at a current density of 6.8 A/dm2 at a temperature of 20° C. Customary working up of the electrolysed mixture and fractional distillation gave 24.5 g of 3-methyl-2-pyrazoline and 29.5 g of 3-methylpyrazole (boiling point 127°-131° C./98 mbar). This corresponds to a conversion of 75%, a yield of 30% and a selectivity of 40%. at a temperature of 20° C Customary working up of the electrolysed mixture and fractional distillation