反应详情

A solution of borane dimethyl sulfide complex (2M in THF, 220 mL) was added portionwise over 5 minutes to a suspension of 3-(carboxymethyl)-2-chlorobenzoic acid [Aromatic Intermediate 11, step c] (18.9 g) in dry THF (800 mL) at room temperature. The resulting effervescing suspension was stirred at room temperature for 30 minutes, then heated to reflux for 60 minutes, and allowed to cool to room temperature overnight. The mixture was quenched by the portionwise addition of methanol (100 mL) over 15 minutes and stirred until bubbling ceased. Concentrated aqueous HCl (25 mL) was added, the mixture was stirred for 30 min and concentrated under reduced pressure. The gummy residue was partitioned between ethyl acetate (500 mL) and aqueous HCl (2M, 200 mL). The phases were separated and the aqueous phase extracted with ethyl acetate (2×300 mL). The combined organic phases were washed with brine (300 mL), dried over magnesium sulphate, filtered and evaporated to give the subtitled compound as a yellow oil. Yield 17.8 g.

1. temperatureheated
2. temperatureto reflux for 60 minutes
3. temperatureto cool to room temperature overnight
4. customThe mixture was quenched by the portionwise addition of methanol (100 mL) over 15 minutes
5. stirringstirred
6. customuntil bubbling
7. additionConcentrated aqueous HCl (25 mL) was added
8. stirringthe mixture was stirred for 30 min
9. concentrationconcentrated under reduced pressure
10. customThe gummy residue was partitioned between ethyl acetate (500 mL) and aqueous HCl (2M, 200 mL)
11. customThe phases were separated
12. extractionthe aqueous phase extracted with ethyl acetate (2×300 mL)
13. washThe combined organic phases were washed with brine (300 mL)
14. dry with materialdried over magnesium sulphate
15. filtrationfiltered
16. customevaporated