PROBLEM TO BE SOLVED: To provide methods for preparing zilpaterol and salts thereof to increase weight gain of livestock, poultry and the like.SOLUTION: A method for preparing zilpaterol comprises: making chloro 2,3-dihydro-2-oxo-lH-benzimidazol-1-butanoate by reacting 4-(2-oxo-2,3-dihydrobenzimidazol-1-yl)butyric acid with a chlorinating agent, such as oxalyl chloride, phosgene, and triphosgene producing 4,5-dihydro-imidazo[4,5,1-jk][1]benzazepin-2,6,7[1H]-trione-6-oxime by reacting 8,9-dihydro-2H,7H-2,9a-diazabenzo[cd]azulene-l,6-dione via a Friedel-Crafts reaction and then by reacting the resultant reaction product with an inorganic nitrite. The zilpaterol is expressed by the following formula.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】家畜、家禽等の体重増加の為、ジルパテロール及びこの塩の製造方法の提供。【解決手段】4-(2-オキソ-2,3-ジヒドロベンゾイミダゾール-1-イル)酪酸を、塩化オキサリル、ホスゲン及びトリホスゲン等の塩素化剤と反応させてクロロ2,3-ジヒドロ-2-オキソ-1H-ベンゾイミダゾール-1-ブタノエートを製造し、更に、フリーデルクラフツ反応等により8,9-ジヒドロ-2H,7H-2,9a-ジアザベンゾ[cd]アズレン-1,6-ジオンを生成させ、反応物と無機亜硝酸塩と反応させることを含む方法による4,5-ジヒドロ-イミダゾ[4,5,1-jk][1]ベンゾアゼピン-2,6,7[1H]-トリオン-6-オキシムの製造し、下記式で表される、ジルパテロールを調整する方法。【選択図】なし
