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US 5,399,783 AGranted
Preparation of 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsMizuo Ito, Shigeru Iimuro
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AssigneeMitsui Toatsu Chemicals, Inc.
InventorsMizuo Ito, Shigeru Iimuro
Estimating the term…
Crystals of 6,6'-dihydroxy-3,3,3',3'-tetramethyl -1,1'-spirobiindane (hereinafter referred to as SPI) are obtained by cooling a phenol solution containing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane when crystallization is started at a temperature higher than a transition temperature between SPI and an adduct of SPI with phenol. The crystals are washed with an organic solvent or contacted with water and further washed with an organic solvent. When crystallization is started at a temperature less than the transition temperature, adduct crystals of SPI with phenol are obtained from the phenol solution. Phenol is removed from the adduct crystals and the adduct crystals are contacted with water to obtain a hydrate and further the hydrate is washed with an organic solvent.
A process for preparing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane which comprises cooling a phenol solution containing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane to carry out crystallization, and recovering crystals comprising 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane.
A process for preparing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane which comprises cooling a solution to carry out crystallization, said solution being obtained by adding at least one organic solvent selected from the group consisting of benzene, toluene, cyclohexane, methylene choloride and chloroform into a reaction mixture obtained by heating 2,2-bis(4-hydroxyphenyl)propane in the presence of an acid catalyst, and recovering crystals comprising 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane.
A process for preparing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane which comprises cooling a solution to carry out crystallization, said solution being obtained by dissolving crude 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane in phenol and further adding thereinto at least one organic solvent selected from the group consisting of benzene, toluene, cyclohexane, methylene choloride and chloroform, and recovering crystals comprising 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane.
Dependencies are inferred from the claim text.