1,3-dibenzylurea

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

Procedure: Cyanoacetyldimethylurea is prepared in analogy to Example 1. Instead of dibenzylurea, dimethylurea is employed. The product is worked up by stripping off the acetic anhydride/acetic acid mixture on a rotary evaporator under reduced pressure. The residue obtained in this way is recrystallized from water. on a rotary evaporator under reduced pressure The residue obtained in this way is recrystallized from water

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

Procedure: 36.0 g (0.15 mol) of dibenzylurea, 15.3 g (0.18 mol) of cyanoacetic acid and 30.6 g (0.3 mol) of acetic anhydride are stirred at 80-85° C. for 2 hours. After cooling, the reaction mixture is stirred into 600 ml of water and the resultant precipitate is filtered off with suction and then dried to constant weight. After cooling the resultant precipitate is filtered off with suction dried to constant weight

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

Procedure: Cyanoacetyldimethylurea is prepared in analogy to Example 1. Instead of dibenzylurea, dimethylurea is employed. The product is worked up by stripping off the acetic anhydride/acetic acid mixture on a rotary evaporator under reduced pressure. The residue obtained in this way is recrystallized from water. on a rotary evaporator under reduced pressure The residue obtained in this way is recrystallized from water

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

Procedure: Cyanoacetyldimethylurea is prepared in analogy to Example 1. Instead of dibenzylurea, dimethylurea is employed. The product is worked up by stripping off the acetic anhydride/acetic acid mixture on a rotary evaporator under reduced pressure. The residue obtained in this way is recrystallized from water. on a rotary evaporator under reduced pressure The residue obtained in this way is recrystallized from water

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

Procedure: 36.0 g (0.15 mol) of dibenzylurea, 15.3 g (0.18 mol) of cyanoacetic acid and 30.6 g (0.3 mol) of acetic anhydride are stirred at 80-85° C. for 2 hours. After cooling, the reaction mixture is stirred into 600 ml of water and the resultant precipitate is filtered off with suction and then dried to constant weight. After cooling the resultant precipitate is filtered off with suction dried to constant weight

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

Procedure: 36.0 g (0.15 mol) of dibenzylurea, 15.3 g (0.18 mol) of cyanoacetic acid and 30.6 g (0.3 mol) of acetic anhydride are stirred at 80-85° C. for 2 hours. After cooling, the reaction mixture is stirred into 600 ml of water and the resultant precipitate is filtered off with suction and then dried to constant weight. After cooling the resultant precipitate is filtered off with suction dried to constant weight

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

Procedure: Heated was a mixture of N,N′-dibenzylurea 12.02 g (50.0 mmol) and malonic acid 5.20 g (50.0 mmol) in acetic anhydride 50.0 mL (530 mmol, 10.6 equivalents) at 70° C.-75° C. for 14 hours under a nitrogen atmosphere. Then, removed were the volatile materials under the reduced pressure and distributed the residue between layers of 2 M sodium hydroxide 250 mL and ether 200 mL. Separated was the alkaline aqueous layer and after washing with ether, neutralized with concentrated hydrochloric acid under cooling in ice-water bath (pH 2-3). Extracted was the neutrallized aqueous solution with chloroform, washed with water, and dried over sodium sulfate. Removal of the solvent under reduced pressure gave 1,3-dibenzylbarbituric acid 14.7 g as pale yellow crystalline powder (95.6% yield). Heated Then, removed Separated after washing with ether, neutralized with concentrated hydrochloric acid under cooling in ice-water bath (pH 2-3) Extracted washed with water dried over sodium sulfate Removal of the solvent under reduced pressure

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

Procedure: Heated was a mixture of N,N′-dibenzylurea 12.02 g (50.0 mmol) and malonic acid 5.20 g (50.0 mmol) in acetic anhydride 50.0 mL (530 mmol, 10.6 equivalents) at 70° C.-75° C. for 14 hours under a nitrogen atmosphere. Then, removed were the volatile materials under the reduced pressure and distributed the residue between layers of 2 M sodium hydroxide 250 mL and ether 200 mL. Separated was the alkaline aqueous layer and after washing with ether, neutralized with concentrated hydrochloric acid under cooling in ice-water bath (pH 2-3). Extracted was the neutrallized aqueous solution with chloroform, washed with water, and dried over sodium sulfate. Removal of the solvent under reduced pressure gave 1,3-dibenzylbarbituric acid 14.7 g as pale yellow crystalline powder (95.6% yield). Heated Then, removed Separated after washing with ether, neutralized with concentrated hydrochloric acid under cooling in ice-water bath (pH 2-3) Extracted washed with water dried over sodium sulfate Removal of the solvent under reduced pressure

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

Procedure: Heated was a mixture of urea 5.84 g (9.72 mmol) and benzylamine 25.0 g (23.3 mmol, 2.4 equivalents) at 150° C.-155° C. for 5 hours attaching with an air cooler. During the heating, observed was the ammonia gas evolution from colorless liquid reaction mixture. By cooling, it turned solidified at around room temperature. Purified was the reaction product by recrystallization from ethanol-benzene (1:1 mixture) to give N,N′-dibenzylurea 14.0 g as white fine needles (59.9% yield). Heated from colorless liquid reaction mixture By cooling turned solidified at around room temperature Purified by recrystallization from ethanol-benzene (1:1 mixture)

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

Procedure: Heated was a mixture of urea 5.84 g (9.72 mmol) and benzylamine 25.0 g (23.3 mmol, 2.4 equivalents) at 150° C.-155° C. for 5 hours attaching with an air cooler. During the heating, observed was the ammonia gas evolution from colorless liquid reaction mixture. By cooling, it turned solidified at around room temperature. Purified was the reaction product by recrystallization from ethanol-benzene (1:1 mixture) to give N,N′-dibenzylurea 14.0 g as white fine needles (59.9% yield). Heated from colorless liquid reaction mixture By cooling turned solidified at around room temperature Purified by recrystallization from ethanol-benzene (1:1 mixture)

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

Procedure: Cyanoacetyldimethylurea is prepared in analogy to Example 1. Instead of dibenzylurea, dimethylurea is employed. The product is worked up by stripping off the acetic anhydride/acetic acid mixture on a rotary evaporator under reduced pressure. The residue obtained in this way is recrystallized from water. on a rotary evaporator under reduced pressure The residue obtained in this way is recrystallized from water

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

Procedure: 36.0 g (0.15 mol) of dibenzylurea, 15.3 g (0.18 mol) of cyanoacetic acid and 30.6 g (0.3 mol) of acetic anhydride are stirred at 80-85° C. for 2 hours. After cooling, the reaction mixture is stirred into 600 ml of water and the resultant precipitate is filtered off with suction and then dried to constant weight. After cooling the resultant precipitate is filtered off with suction dried to constant weight