Sodium Hydroxide → 5-Chloro-2-(trifluoromethyl)pyridine

19.91 g of 2-hydrazino-3-chloro-6-trifluoromethyl pyridine from the small batch and 30.19 g from the large batch were combined (50.10 g total, 0.237 mol) in a 2 L, three-neck flask with a mechanical stirrer and an addition funnel. Dichloromethane (190 g) and sodium hydroxide (237 g, 1N solution) were added to the flask. Sodium hypochlorite (NaOCl) (354 g, 0.238 mol, 5% solution) was charged to the addition funnel. The sodium hypochlorite solution was added over 1 hour as the solution turned yellow, then orange, and then purple-brown. The conversion was approximately 36% at the end of the sodium hypochlorite addition. The solution was stirred for an additional 6.5 hours, at which point the conversion was about 98%. Agitation was stopped and the solution was left overnight. The next morning, sodium hypochlorite (9 g, 0.006 mol, 5% solution) was added, and the solution was stirred for 1.5 hours, at which point sampling indicated that there was less than 1% starting material. The layers were separated and the aqueous layer was extracted twice with dichloromethane (100 mL). The organic layers were combined, washed with water, dried with magnesium sulfate, filtered, and concentrated on the rotovap to give 46.44 g of crude 3-chloro-6-trifluoromethyl pyridine.

1. waitthe solution was left overnight
2. stirringthe solution was stirred for 1.5 hours, at which point
3. aliquotsampling
4. customThe layers were separated
5. extractionthe aqueous layer was extracted twice with dichloromethane (100 mL)
6. washwashed with water
7. dry with materialdried with magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated on the rotovap

ORD record

ord-6bf84afe374640b2883c2913e5498b89

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08785650B2