1,4-dichloro-2-isocyanatobenzene

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

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

Procedure: To 6.73 g. (0.05 mole) of 1-methyl-2-iminopyrrolidine HCl is added 1 ml. of water and 50 ml. of benzene. After solution is complete (magnetic stirring), 10 ml. of aqueous sodium hydroxide (50%) is added in one portion. After stirring for about 1 min., the benzene layer is decanted onto anhydrous potassium carbonate. The extraction is repeated twice. After drying (occasional swirling) the combined benzene extracts are filtered (dicalite) from drying agent and 9.4 g. (0.05 mole) of 2,5-dichlorophenylisocyanate is added to the filtrate in one portion with swirling. After stirring for 3 hours, the solvent is removed in vacuo affording a colorless solid, 1-(2,5-dichlorophenyl)-3-(1-methyl-2-pyrrolidylidene)urea. Recrystallization from acetone (twice) yields the pure product, m.p. = 148.5°-150.5° C. After stirring for about 1 min. the benzene layer is decanted onto anhydrous potassium carbonate The extraction After drying (occasional swirling) the combined benzene extracts are filtered (dicalite) from drying agent and 9.4 g After stirring for 3 hours the solvent is removed in vacuo

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

Procedure: To 6.73 g. (0.05 mole) of 1-methyl-2-iminopyrrolidine HCl is added 1 ml. of water and 50 ml. of benzene. After solution is complete (magnetic stirring), 10 ml. of aqueous sodium hydroxide (50%) is added in one portion. After stirring for about 1 min., the benzene layer is decanted onto anhydrous potassium carbonate. The extraction is repeated twice. After drying (occasional swirling) the combined benzene extracts are filtered (dicalite) from drying agent and 9.4 g. (0.05 mole) of 2,5-dichlorophenylisocyanate is added to the filtrate in one portion with swirling. After stirring for 3 hours, the solvent is removed in vacuo affording a colorless solid 1-(2,5-dichlorophenyl)-3-(1-methyl-2-pyrrolidylidene)urea. Recrystallization from acetone (twice) yields the pure product, m.p. = 148.5°-150.5° C. After stirring for about 1 min. the benzene layer is decanted onto anhydrous potassium carbonate The extraction After drying (occasional swirling) the combined benzene extracts are filtered (dicalite) from drying agent and 9.4 g After stirring for 3 hours the solvent is removed in vacuo

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

Procedure: The solution of 4.7 g of 1-phenyl-3-methyl-2-pyrazolin-5-one in 75 ml of benzene and 3.3 g of triethylamine is combined with the solution of 5.1 g of 2,5-dichlorophenylisocyanate in 25 ml of benzene. After warming the mixture briefly on the steam cone, the resulting solution is allowed to stand for 2 hours at room temperature. It is evaporated, the residue triturated with diethyl ether and recrystallized from methanol-diethyl ether to yield the triethylammonium salt-methanolate of the 1-phenyl-3-methyl-4-(2,5-dichlorophenylcarbamoyl)-2-pyrazolin-5-one, melting at 142°-147°, resolidifying and remelting at 154°-159°. After warming the mixture briefly on the steam cone It is evaporated the residue triturated with diethyl ether recrystallized from methanol-diethyl ether