HCID 21249770, compound → HCID 21249775, compound

Participants

Reaction Conditions

Reaction Steps

8.3 g of 5% palladium carbon, 83.0 g (0.244 mol) of 2-(3,5-dinitrophenylureido)ethyl isobutyrate (compound 12) and 800 ml of ethanol were placed in a 5-l autoclave equipped with a thermocouple thermometer and a mixing blade, and the autoclave was sealed. The atmosphere inside the autoclave was replaced by hydrogen and the hydrogen pressure was raised to 5 kg/cm2. The autoclave contents were stirred at room temperature (17° C.). Ten minutes later, the autoclave inside temperature rose to 43° C. and the autoclave inside pressure dropped to 1 kg/cm2. Then, hydrogen was introduced to raise the pressure to 5 kg/cm2, and stirring was continued. Ten minutes later, the temperature became 58° C. and the pressure dropped to 1 kg/cm2. Hydrogen was again introduced to raise the pressure to 5 kg/cm2, and stirring was continued. Since the temperature began to drop and the pressure became constant (4.5 kg/cm2), stirring was continued for 60 minutes (the temperature dropped to 26° C.). The atmosphere inside the autoclave was replaced by nitrogen, and the autoclave contents were taken out and filtered to remove palladium carbon. The filtrate was concentrated by the use of an evaporator, whereby a solid was separated. The solid was recrystallized from 300 ml of butanol to obtain 2-(3,5-diaminophenylureido)ethyl isobutyrate (compound 13). Yield: 55.0 g (81%) Melting point: 89-90° C.

Provenance & Evidence