PROCEDEU DE PREPARARE A UNOR DINITROANILINE CU ACTIUNE ERBICIDA

摘要

Prepn. of herbicidal cpds. of formula (I) (where Y is 1-4C alkyl, halogen CF3; Z is H, halogen; 1-4C alkyl opt. substd. by one halogen or 1-4C alkoxy; 1-4C alkoxy; Ra is 1-6C alkyl, 4-6C cycloalkyl, 1-4C alkoxy - 1-4C alkyl; Rb is H or one of the values of Ra) comprises nitration of the corresp. N-alkylanilines with a mixed acid within the limits 60% HNO3 8% H2SO4, 32% H2O; 50% HNO3, 35% H2SO4, 15% H2O; 2% HNO3, 68% H2SO4, 30% H2O; 2% HNO3, 20% H2SO4, 70% H2O AT 0-70 degrees C. The process avoids the need to block the amino gp. by acylation when Rb is H. This is overcome by denitrosation of the by-prod. N-nitroso cpd. by treating it with HC1 and sulphamic acid.