Back to results
US 6,320,060 B1Granted
Process for producing 5-hydroxybenzo[b] thiophene-3-carboxylic acid derivatives
AssigneeShionogi & Co., Ltd.
InventorsTsunetoshi Honma, Yoshiharu Hiramatsu
Life of this patent
Estimating the term…
Abstract
Benzothiophenecarboxylic acid derivatives of the formula (I) which are useful as starting materials for producing drugs, and a process for preparing 5-hydroxybenzo[b]-thiophene-3-carboxylic acid derivatives of the formula (VI) which are specific PGD2 antagonists.
Claims8
A process for producing a compound of the formula (I):
- wherein R is hydrogen or a hydroxy-protecting group, or a reactive derivative thereof, which comprises introducing a propargyl group into 4-mercaptophenol, and protecting the hydroxyl group of the 4-mercaptophenol, to yield a compound of the formula (II):
- wherein R1 is a hydroxy-protecting group, oxidizing the compound (II) to yield a compound of the formula (III):
- wherein R1 is a hydroxy-protecting group;
- subjecting the compound (III) to a thermal rearrangement reaction to yield a compound of the formula (IV):
- wherein R1 is as defined above;
- and subjecting the compound (IV) to stepwise oxidation of the hydroxymethyl group and optionally deprotection.
3 more elements
A compound of the formula (I):
- wherein R is arylsulfonyl or a reactive derivative thereof.
A compound of the formula (I):
- wherein R is benzenesulfonyl or a reactive derivative thereof.
Dependencies are inferred from the claim text.