5-Chloro-2-methoxybenzenebutanoic acid → 34910-81-1

A flask containing 1600 g. of polyphosphoric acid and 160 g. (0.70 mole) 4-(5-chloro-2-methoxyphenyl)butyric acid was heated on a steam bath (internal temperature 90°-95° C.) for 1.5 hours. The hot reaction mixture was then poured onto 2 liters of crushed ice with stirring. The quenched mixture was stirred for 30 minutes, then extracted 3 times with 500 ml. portions of chloroform, the extract carbon treated, dried with MgSO4 and filtered. The filtrate was concentrated in vacuo to afford 146 g. of dark oil. This was dissolved in ether, washed with aqueous NaHCO3, then water, carbon treated, dried over MgSO4 and evaporated to dryness. The oil thus produced was distilled under high vacuum to obtain 65.4 g. of product (44% yield). Upon cooling the distillate it crystallized, m.p. 46°-48° C.

1. additionA flask containing 1600 g
2. stirringThe quenched mixture was stirred for 30 minutes
3. extractionextracted 3 times with 500 ml
4. additionportions of chloroform, the extract carbon treated
5. dry with materialdried with MgSO4
6. filtrationfiltered
7. concentrationThe filtrate was concentrated in vacuo
8. customto afford 146 g
9. washwashed with aqueous NaHCO3
10. additionwater, carbon treated
11. dry with materialdried over MgSO4
12. customevaporated to dryness
13. customThe oil thus produced
14. distillationwas distilled under high vacuum
15. customto obtain 65.4 g

ORD record

ord-df6147464d8149e68de49c1e0b0bc75f

Source dataset

uspto-grants-1977_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04022791