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US 6,555,718 B1Granted
Process for preparing 3,3′,6,6′-tetraalkyl-2,2′-biphenols and 3,3′,6,6′-tetraalkyl-5,5′-dihalo-2,2′-biphenols
AssigneeE. I. Du Pont de Nemours and Company
InventorRafael Shapiro
Life of this patent
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Abstract
A process for making a compound of the formula I
Claims7
A process for making a compound of the formula IV
- wherein
- R1 is C1 to C10 primary or secondary alkyl or cycloalkyl,
- R4 is C1 to C10 primary or secondary alkyl or cycloalkyl, and
- X is H, Cl, Br, or I
- comprising:
- (1) when X is H
- (a) alkylating a compound of the formula V
- at the 4-position thereof to produce a compound of the formula VI
- wherein R3 is C4 to C20 tertiary alkyl,
- (b) oxidatively coupling the compound of the formula VI to produce a compound of the formula VII
- (c) dealkylating a compound of the formula VII to produce a compound of the formula IV wherein X is H;
- and
- (2) when X is Cl, Br, or I
- (a) alkylating a compound of the formula V at the 4-position thereof to produce a compound of the formula VI,
- (b) oxidatively coupling the compound of the formula VI to produce a compound of the formula VII,
- (c) dealkylating a compound of the formula VII to produce a compound of the formula IV wherein X is H, and
- (d) substituting Cl, Br, or I, respectively, for H at the 5 and 5′ positions of the compound of the formula IV wherein X is H.
14 more elements
Dependencies are inferred from the claim text.