| 摘要 |
2, 21, 4, 41-Tetrabromo-N-(C1-5 alkyl) diphenylamines of the formula: <FORM:0979388/C1/1> where R is a C1-5 alkyl radical, by contacting an N-(C1-5 alkyl) diphenylamine with at least 4 moles of bromine per mole of the amine in a solvent system comprising water and an inert, non-polar, water-immiscible, organic solvent. Suitable solvents are ethers such as dialkyl ethers; aliphatic hydrocarbons such as hexane, heptane and octane; chlorinated hydrocarbons such as chloroform, carbon tetrachloride and ethylene chloride; and aromatic hydrocarbons such as benzene and toluene. Preferably the solvent system should comprise at least 2%, more preferably 15 to 75%, water by volume while the ratio of water to N-alkyl diphenylamine is at least one mol., more preferably between 4 and 12 mols., per g. of amine. It is preferable to add a small amount of a base at least as strong as water but not stronger than aqueous sodium carbonate. Suitable bases are sodium carbonate, sodium bicarbonate and calcium carbonate. Detailed examples are given. |
