2-(3,5-Dichloro-4-hydroxyphenyl)ethanol → 2-[3,5-Dichloro-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-ethanol

Temperature

100 °C

A mixture of 2,6-dichloro-4-(2-hydroxy-ethyl)-phenol (16) (12.5 g, 60.2 mmol) in N,N-dimethyl acetamide (28 mL) was treated with potassium tert-butoxide (6.5 g, 57.8 mmol) under nitrogen at room temperature. The suspension was heated to 100° C. and stirred until a solution formed. The reaction was then treated with 3,6-dichloro-4-isopropyl pyridazine (7) (9.2 g, 48 mmol) followed by a rinse with N,N-dimethyl acetamide (3 mL). The reaction mixture was stirred at 135° C. for 24 h. The reaction was cooled to room temperature, diluted with water (30 mL) and extracted with tert-butyl methyl ether (1×60 mL) followed by isopropyl acetate (1×60 mL). The organic layers were combined and were washed with a 1N aqueous sodium hydroxide solution (1×25 mL) and water (2×25 mL). The organic layer was separated and distilled to a volume of approximately 30 mL. This solution was treated with heptane (30 mL). The mixture was stirred under reflux for 30 min and then cooled to room temperature. The resulting solid was filtered, washed with ether and dried overnight to afford 2-[3,5-dichloro-4-(6-chloro-5-isopropyl-pyridazin-3-yloxy)-phenyl]-ethanol (17) (7.5 g, 44%) as a white solid; LRMS for C15H15Cl3N2O2 (M+H) m/z=363. Molecular Weight=361.6580; Exact Mass=360.0199

1. customformed
2. washa rinse with N,N-dimethyl acetamide (3 mL)
3. stirringThe reaction mixture was stirred at 135° C. for 24 h
4. temperatureThe reaction was cooled to room temperature
5. additiondiluted with water (30 mL)
6. extractionextracted with tert-butyl methyl ether (1×60 mL)
7. washwere washed with a 1N aqueous sodium hydroxide solution (1×25 mL) and water (2×25 mL)
8. customThe organic layer was separated
9. distillationdistilled to a volume of approximately 30 mL
10. additionThis solution was treated with heptane (30 mL)
11. stirringThe mixture was stirred
12. temperatureunder reflux for 30 min
13. temperaturecooled to room temperature
14. filtrationThe resulting solid was filtered
15. washwashed with ether
16. customdried overnight

ORD record

ord-74186e48a6c3448c924fdd152df64e7e

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

USRE046024E1