Carbon Dioxide → HCID 51064101, compound
Reaction equation
[OH:1][C:2]1[CH:13]=[CH:12][C:5]([O:6][C@H:7]([CH3:11])[C:8]([OH:10])=[O:9])=[CH:4][CH:3]=1.[K].C(=O)([O-])[O-].[K+].[K+].[C:21](=O)=O.[Cl:24][C:25]1[CH:26]=[C:27]([F:32])[C:28](F)=[N:29][CH:30]=1.[C:33](#N)[CH3:34]>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC>[C:21]([O:9][C:8](=[O:10])[C@H:7]([O:6][C:5]1[CH:4]=[CH:3][C:2]([O:1][C:28]2[C:27]([F:32])=[CH:26][C:25]([Cl:24])=[CH:30][N:29]=2)=[CH:13][CH:12]=1)[CH3:11])#[C:33][CH3:34]Participants
Reactant 6
Product 1
Reagents, catalysts & solvents 1
Procedure
182 g of (R)-2-(p-hydroxyphenoxy)-propionic acid 100% (1 mol) in 1500 g of acetonitrile are converted into the corresponding potassium salt by adding 69 g of potassium carbonate powder (0.5 mols) at 70° C. whilst cleaving the CO2. Then, 193 g of potassium carbonate powder (1.4 mols) and 2 g of tetrabutyl ammonium bromide as the phase transfer catalyst are added to the reaction mixture, and at a temperature of 70 to 75° C., 165 g of 5-chloro-2,3-difluoropyridine (1.1 mols) are added over the course of 30 minutes. After 8 hours, the compound of formula V thus obtained is reacted totally to form the (R)(+)-2-[4-(5-chloro-3-fluoropyridin-2-yloxy)-phenoxy]-propionic acid propinyl ester, directly, without isolation, at a temperature of 70-75° C., by measuring in chloroformic acid propargyl ester, whereby CO2 is released. Working up is effected analogously to example P1. (R)(+)-2-[4-(5-chloro-3-fluoropyridin-2-yloxy)-phenoxy]-propionic acid propinyl ester is obtained with a content of 97% (GC), corresponding to a yield of 80% of theory, based on (R)-2-(p-hydroxyphenoxy)-propionic acid.
Workup
- customthe compound of formula V thus obtained
- customis reacted totally
Sources & evidence
- ORD record
- ord-e90cfc9b0ee94c30a37702b6b0c84554
- Source dataset
- uspto-grants-2001_01
- Patent number
- US06175018B1
Reaction notes
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