摘要:
Olefins are epoxidized by hydrogen peroxide in the presence of an organorhenium oxide catalyst and an alkyl aryl secondary alcohol solvent. High yields of epoxides with minimal non-selective loss of either hydrogen peroxide or olefin are realized. The epoxidation may comprise one step of an integrated process wherein an oxidant mixture is generated by molecular oxygen oxidation of the alkyl aryl secondary alcohol and used directly in the epoxidation without further purification or extraction.
摘要:
A multi-step process for the preparation of an aliphatic mono-, di- or poly- isocyanate from primary aliphatic amines and isocyanic acid to form an aliphatic urea which is then reacted with a dialkyl amine to give a mono-, di- or poly- (dialkyl) urea which is then thermally treated in the presence of a reaction promoter to produce the desired isocyanate.
摘要:
A multi-step process for the preparation of methylene diphenylene diisocyanates (MDI) or polymethylene polyphenylene poly (isocyanates) (PMDI) from methylene diphenylene diamines or polymethylene polyphenylene polyamines comprises reacting the diamine or polyamine with isocyanic acid to form a urea which is then reacted with a dialkyl amine to give a corresponding dialkyl urea or poly (alkyl urea) product which is then thermally reacted in the presence of various reaction promoters to give the corresponding isocyanate MDI or PMDI product.
摘要:
A multi-step process for the preparation of aromatic mono- and polyisocyanates in which an aromatic mono- or polyamine and isocyanic acid are reacted to form an aromatic urea which is then reacted with a dialkyl amine to give an aromatic dialkyl urea product. The aromatic dialkyl urea is thermally treated in an inert organic solvent in the presence of a reaction promoter to produce the isocyanate.