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US 9,809,543 B2Granted
Method for producing 2,3-dichloro-5-(trichloromethyl)pyridine
AssigneeCheminova A/S
InventorCasper Stoubaek Andersen
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Abstract
The present invention relates to a novel process for producing of 2,3-dichloro-5-(trichloromethyl)pyridine by using PCl as chlorinating agent at elevated temperature and pressure.
Claims32
A method for preparing 2,3-dichloro-5-(trichloromethyl)pyridine of formula [II] by a process which comprises the steps:
- (1) preparing a reaction mixture comprising a compound of the general formula [I] and PCl5,
- wherein
- (i) X is COOH, CONH2, CCl3, or CN;
- (ii) R1 represents H or Cl;
- and
- (iii) PCl5 acts as a chlorinating agent;
- and
- (2) reacting said mixture at a pressure above 1 bar and a temperature above 70° C. and below 350° C.;
- wherein, when R1 is H, an intermediate compound (A), 2-chloro-5-(trichloromethyl)pyridine, is formed;
- or
- when R1 is H and X is COOH, an intermediate (B), 3-chloroformylpyridine, is formed;
- or
- when R1 is Cl and X is COOH, an intermediate (B), 3-chloroformyl-5-chloropyridine, is formed in the process.
10 more elements
Dependencies are inferred from the claim text.