2,6-Lutidine → 2,6-Bis(trifluoromethyl)-3-methoxycarbonyl-4-chloropyridine

Reaction equation

[F:1][C:2]([F:19])([F:18])[C:3]1[C:8]([C:9]([O:11][CH3:12])=[O:10])=[C:7](O)[CH:6]=[C:5]([C:14]([F:17])([F:16])[F:15])[N:4]=1.N1C(C)=CC=CC=1C.O=P(Cl)(Cl)[Cl:30]>>[F:1][C:2]([F:19])([F:18])[C:3]1[C:8]([C:9]([O:11][CH3:12])=[O:10])=[C:7]([Cl:30])[CH:6]=[C:5]([C:14]([F:17])([F:16])[F:15])[N:4]=1

Participants

Reactant 3

HCID 79372,6-Lutidine

HCID 24813Phosphorus oxychloride

HCID 178498966Methyl 2,6-bis(trifluoromethyl)-4-hydroxy-3-pyridinecarboxylate

Product 1

HCID 138828782,6-Bis(trifluoromethyl)-3-methoxycarbonyl-4-chloropyridineYield 19.7%

Procedure

A mixture of 6.7 g (0.0232 mol) of product of Example 4, 2.8 g (0.026 mol) of 2,6-lutidine, and 50 ml of POCl3 was held at reflux for 18 hours and concentrated. The residue was treated with water and extracted with ether. The ether extract was washed with 10% NaOH and then with saturated NaCl, dried, and concentrated. The residue was kugelrohr distilled at 133 Pa (pot temperature 90° C.). The distillate was recrystallized from hexane at low temperature to give 1.4 g (19.7%) of product; mp 48°-49° C.