84224-55-5

Upstream product

• 431-03-8 dimethylglyoxal 
• 108-95-2 phenol 
• 7664-93-9 sulfuric acid 
• 64-19-7 acetic acid 
• 7732-18-5 water 
• 22800-75-5 2,3-bis-(4-hydroxy-phenyl)-butane-2,3-diol 
• 10034-85-2 hydrogen iodide 
• 99-93-4 4-Hydroxyacetophenone 

Downstream Products

• 22927-05-5 3,3-bis-(4-methoxy-phenyl)-butan-2-one 
• 2962-14-3 meso-Butestrol 
• 2962-14-3 racem.-2,3-bis-(4-hydroxy-phenyl)-butane 

Relevant academic research and scientific papers

Method for preparing aromatic bischloroformate compositions

Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueous to organic phase. By this method, it is possible to employ a minimum amount of phosgene. The reaction may be conducted batchwise or continuously. The bischloroformate composition may be employed for the preparation of cyclic polycarbonate oligomers or linear polycarbonate, and linear polycarbonate formation may be integrated with bischloroformate composition formation in a batch or continuous process.

Bischoloroformate preparation method with phosgene removal and monochloroformate conversion

Aqueous bischloroformates are prepared by the reaction of a dihydroxyaromatic compound (e.g., bisphenol A) with phosgene in a substantially inert organic liquid (e.g., methylene chloride) and in the presence of an aqueous alkali metal or alkaline earth metal base, at a pH below about 8. After all solid dihydroxyaromatic compound has been consumed, the pH is raised to a higher value in the range of about 7-12, preferably 9-11, and maintained in said range until a major proportion of the unreacted phosgene has been hydrolyzed. At the same time, any monochloroformate in the product may be converted to bischloroformate.

Cyclic monocarbonate bishaloformates

Cyclic monocarbonate bischloroformates are prepared by the reaction of a carbonyl halide such as phosgene with a bridged substituted resorcinol or hydroquinone such as bis(2,4-dihydroxy-3-methylphenyl)methane or bis(2,5-dihydroxy-3,4,6-trimethylphenyl)methane in the presence of aqueous alkali metal hydroxide. The cyclic monocarbonate bischloroformates may be used for the preparation of linear or cyclic polycarbonates containing cyclic carbonate structural units, which may in turn be converted to crosslinked polycarbonates.

Polyetherimide bisphenol compositions

Polyetherimide bisphenols and bischloroformates are prepared by the reaction of dianhydrides or certain bisimides with aminophenols or mixtures thereof with diamines. They are useful as intermediates for the preparation of cyclic heterocarbonates, which may in turn be converted to linear copolycarbonates. The bisphenols can also be converted to salts which react with cyclic polycarbonate oligomers to form block copolyetherimidecarbonates.

Stereochemistry and Side Products in Reductive Coupling of Alkyl Aryl Ketones to 1,2-Dialkyl-1,2-diarylethylenes

The reductive coupling of alkyl aryl ketones 1 - 3 and 7 - 9 by low valent titanium salts yields predominantly the (Z)-isomers of 11 - 13 and 17 - 19.Evidence is given by 1H NMR spectroscopy.This behavior can be explained by ?-complex formation of phenyl rings with Ti0.Severe steric hindrance, however, favors the (E)-isomers ( -> 14 and 15).Donor groups in p-position, particularly, give increasing amounts of pinacols, 23 - 27, which undergo rearrangement to the ketones 28 and 29.