1-Methoxycarbonyl-3-(2-amino-4-isopropoxycarbonylaminophenyl)thiourea 、
1-Ethoxycarbonyl-3-(2-amino-4-isopropoxycarbonylaminophenyl)thiourea 、
1-methoxycarbonyl-3-(2-amino-4-n-butylphenyl)thiourea 以there were obtained 1-methoxycarbonyl-3-(2-acetamido-4-isopropoxycarbonylaminophenyl)thiourea, m.p. 187°-188° C. (with decomposition) and 1-ethoxycarbonyl-3-(2-acetamido-4-isopropoxycarbonylaminophenyl)thiourea, m.p. 201°-202° C. (with decomposition)的产率得到1-methoxycarbonyl-3-(2-acetamido-4-isopropoxycarbonylaminophenyl)thiourea