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US 5,206,376 AGranted
Preparation of 2-amino-5-formyl-4-halothiazoles
AssigneeBASF SE
InventorsMatthias Wiesenfeldt, Karl-Heinz Etzbach
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Abstract
A process for the preparation of 2-amino-5-formyl-4-halothiazoles by reaction, in a first stage, of thiourea with chloroacetic or bromoacetic acid in the presence of an N,N-disubstituted formamide, followed by treatment of the reaction mixture with a phosphoric trihalide and then with water in the presence of a base.
Claims21
A process for the preparation of 2-amino-5-formyl-4-(chloro or bromo)thiazole, comprising
- a) reacting, in a first stage, thiourea with chloroacetic or bromoacetic acid in the presence of a disubstituted formamide selected from the group consisting of an N,N-di(C.sub.1 -C.sub.4 -alkyl)formamide and an N-(C.sub.1 -C.sub.4 -alkyl)-N-phenylformamide,
- b) treating the reaction mixture, in a second stage, with phosphorus oxide trichloride or phosphorus oxide tribromide, and
- c) treating the reaction mixture, in a third stage, with water in the presence of a base,
- said reacting in said first stage and said treating in said second stage being conducted in a single reactor.
1 more element
Dependencies are inferred from the claim text.