The invention provides novel phenylurea of formula I ##STR1## wherein R.sub.1 is H or CHO, R.sub.2 is H, CH.sub.3 or OCH.sub.3 R.sub.3 is a group G.sub.1 of the formula ##STR2## or a group G.sub.2 of the formula CH(CH.sub.3)CH.sub.2 Y in which Y is halogen selected from Cl or F or is CH.sub.3 O and X is H or halogen selected from Cl or Br, the use of these novel compounds as herbicides, compositions for facilitating such use and the preparation of the novel phenylurea.