Chemical advances in synthesis and reactions of diarylureas

CONTENTS
I. Introduction 634
II. Synthesis of diarylureas by phosgenation of aromatic amines 634
III. Conditions for and mechanism of the phosgenation of aromatic amines 636
IV. Synthesis of diarylureas and arylalkylureas by the reaction of amines with aryl isocyanates 639
V. Synthesis of dialkylureas and diarylureas by the reaction of amines with urea 641
VI. Conditions for and mechanism of the reaction of diarylureas with aromatic amines 644
VII. Synthesis of substituted diarylureas by nitration, chlorination, and sulphonation of diphenylurea 646
VIII. Hydrolysis and other reactions of diarylureas 648
IX. Synthesis of aromatic amines via diarylureas and by other new methods 650