1-Butyl-3-phenylthiourea 6336-01-2 N-Butyl-phenylthiourea N-Phenyl-N'-butylthiourea NSC131981 Thiourea, N-butyl-N'-phenyl- U 19440 Urea, 1-butyl-3-phenyl-2-thio- WLN: SUYM4&MR