Реакция #2286293

Уравнение реакции

hydrochloric acid

lithium aluminum hydride

(3,5-dichloro-4-hydroxy-phenyl)-acetic acid methyl ester

(3,5-Dichloro-4-hydroxy-phenyl)-acetic acid methyl ester

→

2,6-dichloro-4-(2-hydroxy-ethyl)-phenol

Выход 100.1%

2,6-Dichloro-4-(2-hydroxy-ethyl)-phenol

Выход 100.1%

Растворители

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   workup.ADDITIONafter the addition
2. 2
   Другоеwas quenched at −10° C. by the dropwise addition of a 10% aqueous Rochelle's Salt solution (80 mL)
3. 3
   workup.STIRRINGThe reaction suspension was stirred 10 min
4. 4
   workup.ADDITIONEthyl acetate (100 mL) was then added to the suspension
5. 5
   ФильтрацияThe mixture was then filtered
6. 6
   ПромывкаThe solids were rinsed with ethyl acetate (2×500 mL)
7. 7
   ДругоеThe organic layer was separated
8. 8
   ЭкстракцияThe aqueous layer was extracted with ethyl acetate (2×200 mL)
9. 9
   Промывкаwashed with a 0.1N aqueous hydrochloric acid solution, water
10. 10
    СушкаThe organic layer was dried with magnesium sulfate
11. 11
    Фильтрацияfiltered
12. 12
    Концентрированиеconcentrated
13. 13
    Другоеto afford the first crop of solid
14. 14
    Другоеwas placed under high vacuum overnight
15. 15
    Экстракцияwas then re-extracted with ethyl acetate (3×200 mL)
16. 16
    Промывкаwashed with water
17. 17
    СушкаThe organic layer was dried with magnesium sulfate
18. 18
    Фильтрацияfiltered
19. 19
    Концентрированиеconcentrated
20. 20
    Другоеwas placed under high vacuum overnight

Методика

A solution of (3,5-dichloro-4-hydroxy-phenyl)-acetic acid methyl ester (15) (15.7 g, 67.09 mmol) in anhydrous tetrahydrofuran (600 mL) under argon cooled to −10° C. was treated slowly dropwise with a 1 M solution of lithium aluminum hydride in tetrahydrofuran (67.1 mL, 67.1 mmol). The reaction mixture was stirred for 5 min after the addition was complete and was quenched at −10° C. by the dropwise addition of a 10% aqueous Rochelle's Salt solution (80 mL). The reaction suspension was stirred 10 min. Ethyl acetate (100 mL) was then added to the suspension. The mixture was then filtered. The solids were rinsed with ethyl acetate (2×500 mL). The organic layer was separated. The aqueous layer was extracted with ethyl acetate (2×200 mL). The organic layers were combined and washed with a 0.1N aqueous hydrochloric acid solution, water, and a saturated aqueous sodium chloride solution. The organic layer was dried with magnesium sulfate, filtered and concentrated to afford the first crop of solid. The resulting solid was placed under high vacuum overnight. The aqueous layer was acidified to pH=5 by the addition of a 1N aqueous hydrochloric acid solution and was then re-extracted with ethyl acetate (3×200 mL). The organic layers were combined and washed with water and a saturated aqueous sodium chloride solution. The organic layer was dried with magnesium sulfate, filtered and concentrated. The resulting solid was placed under high vacuum overnight to afford 2,6-dichloro-4-(2-hydroxy-ethyl)-phenol (16) (13.9 g, 100%); LRMS for C8H8Cl2O2 (M+) m/z=207 Molecular Weight=207.0578; Exact Mass=205.9901

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