Process for preparing substituted 2-alkoxycarbonyl-3-aminothiophenes
AssigneeBayer CropScience AG
InventorThomas Geller
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Abstract
The present invention relates to a process for preparing 4-alkoxycarbonyl-3-aminothiophenes of the general formula (I) and/or their hydrochlorides of the formula (I)′ in which R1 and R2 are each as defined in the description, and/or their mono- or bisacetylated or mono- or bisformylated form, by reacting enamines of the formula (II) in which R1 and R2 are each as defined in the description, and/or their mono- or bisacetylated or mono- or bisformylated form, with a chlorinating agent in the presence of one or more diluents, and also to a process for preparing the compounds of the formula (II).
Claims16
A process for preparing a 4-alkoxycarbonyl-3-aminothiophene of formula (I)
- and/or a hydrochloride of the formula (I)′
- and/or a mono- or bisacetylated or mono- or bisformylated form of formulae (I)″
- in which
- R1 is optionally halogen- or C1-C4-alkoxy-substituted alkoxy having from 1 to 6 carbon atoms,
- R2 is C1-C4-alkyl-, and
- R3 is an acyl or formyl substituent,
- which comprises reacting
- an enamine of formula (II)
- and/or a mono- or bisacetylated or mono- or bisformylated form of formula (H)″
- with a chlorinating agent in the presence of at least one diluent wherein the diluent is selected from the group consisting of chlorobenzene and methylene chloride.
A process for preparing a compound of formula (II)
- in which
- R1 is optionally halogen- or C1-C4-alkoxy-substituted alkoxy having from 1 to 6 carbon atoms,
- R2 is C1-C4-alkyl-, and
- which comprises reacting a compound of formula (III)
- with ammonium formate, optionally in the presence of NH3, with ammonium acetate, optionally in the presence of NH3, with a mixture of formic acid and NH3 and/or with a mixture of acetic acid and NH3 in the presence of at least one diluent.
Dependencies are inferred from the claim text.