반응 #704878

반응 방정식

CO2

n-butyllithium

title compound

6-bromo-2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]

tetrahydrofuran

→

title compound

2,3-dihydrospiro[4H-1-benzothiopyran-4,2 '[1,3]dioxolane]-6-carboxylic acid

용매

hexane

hexane

반응 조건

후처리

1. 1
   기타the temperature below -55° C
2. 2
   workup.STIRRINGthe mixture was stirred overnight
3. 3
   온도while warming to room temperature
4. 4
   여과was then filtered
5. 5
   workup.ADDITIONTo the solid residue was added 500 mL of water and 400 mL of methylene chloride
6. 6
   온도The solution was cooled to about 0° C.
7. 7
   추출extracted with methylene chloride (3×400 mL)
8. 8
   건조The resulting solution was dried (MgSO4)
9. 9
   여과filtered
10. 10
    기타evaporated to dryness

실험 절차

13.58 g (0.047 mol) of the title compound of Step C was added to 150 mL of tetrahydrofuran. The solution was cooled to about -65° C. and 23 mL (0.057 mol) of 2.5 M n-butyllithium in hexane (purchased from Aldrich Chemical Company) was added dropwise while keeping the temperature below -55° C. After stirring under nitrogen for 1 h, excess solid CO2 was added in one portion, and the mixture was stirred overnight while warming to room temperature. 100 mL of hexane was added to the mixture, and it was then filtered. To the solid residue was added 500 mL of water and 400 mL of methylene chloride. The solution was cooled to about 0° C., acidified to pH 1 with concentrated hydrochloric acid, and extracted with methylene chloride (3×400 mL). The resulting solution was dried (MgSO4), filtered, and evaporated to dryness to yield 8.58 g of the title compound of Step D as a solid melting at 186.7° C. (dec). 1H NMR (Me2SO-d6): δ2.2 (m,2H), 3.2 (m,2H), 4.1 (m,4H), 7.2-8.0 (3H), 12.8 (br s,1H).

출처