Preparation of thiophene compounds
AssigneeEastman Kodak Company
InventorPeter W. Raynolds
Life of this patent
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Abstract
Disclosed is a process for the preparation of thiophenes having the formula ##STR1## by contacting a compound having the formula ##STR2## with certain amine bases. Other amine bases can be employed when a two-phase reaction system is used.
Claims7
Process for the preparation of a compound having the formula ##STR7## which comprises contacting a compound having the formula ##STR8## in an inert solvent with an amine having a pK.sub.b of about 8 to 10, wherein R.sup.1 and R.sup.2 are groups hydrolyzable to carboxyl groups.
A process for the preparation of a compound having the formula ##STR11## which comprises monochlorinating a compound having the formula ##STR12## with a chlorinating agent in an inert solvent to obtain a compound having the formula ##STR13## and contacting the compound of formula (II) in the inert solvent with an amine having a pK.sub.b of about 8 to 10, wherein R.sup.1 and R.sup.2 are groups hydrolyzable to carboxyl groups.
A process for the preparation of a compound having the formula ##STR17## in a two-phase reaction system consisting of an inert, water-immiscible organic solvent and water which comprises contacting a compound having the formula ##STR18## in the organic solvent with a tertiary amine that is soluble in the organic solvent and has a pK.sub.b of about 3 to 5 to obtain a water-soluble intermediate and acidifying the aqueous phase, wherein R.sup.1 and R.sup.2 are groups hydrolyzable to carboxyl groups.
Dependencies are inferred from the claim text.