반응 #74389

반응 방정식

phosphorus-trichloride

Tygon

sodium sulfite

(1S,4R)-bicyclo[2.2.1]heptane-2-carboxylic acid

bromine

→

(4S)-2-bromobicyclo[2.2.1]heptane-1-carboxylic acid

용매

ether

반응 조건

후처리

1. 1
   workup.ADDITIONAfter the addition
2. 2
   온도the reaction mixture was heated in a silicone oil bath at 80° C. for 4 h
3. 3
   온도After this time, the reaction was cooled to 10° C.
4. 4
   온도The reaction was then heated to 80° C
5. 5
   온도The reaction was then cooled to room temperature
6. 6
   기타The ethereal solution was transferred to a separation funnel
7. 7
   세척washed with 1M sodium sulfite (2 (500 mL), water (1 (500 mL), and brine (1 (500 mL)
8. 8
   건조The organic layer was dried over MgSO4
9. 9
   여과filtered
10. 10
    농축concentrated in vacuo
11. 11
    기타to afford an oil
12. 12
    workup.STIRRINGthe mixture was stirred vigorously
13. 13
    workup.WAITAfter 20 min
14. 14
    기타a fine white precipitate formed
15. 15
    여과which was filtered
16. 16
    세척washed with pentane (20 mL)
17. 17
    기타air dried under a gentle vacuum

실험 절차

To a 50 mL round-bottomed flask was added (1S,4R)-bicyclo[2.2.1]heptane-2-carboxylic acid (9.84 g, 70 mmol) and bromine (4.10 ml, 80 mmol). The suspension was stirred at room temperature until dissolution. Trichlorophosphine (0.30 ml, 3.4 mmol) was then added slowly and drop wise (significant exotherm observed). A reflux condenser was fitted to the flask with a nitrogen gas inlet and gas outlet (Tygon tubing) running into a scrubber solution of sodium sulfite (1 M, 200 mL). After the addition was complete, the reaction mixture was heated in a silicone oil bath at 80° C. for 4 h. After this time, the reaction was cooled to 10° C. and phosphorus-trichloride (4.23 ml, 48.3 mmol) was added drop-wise. The reaction was then heated to 80° C. During this time the color intensity of the reaction decreased, and after 8 h, the reaction mixture appeared dark orange. The reaction was then cooled to room temperature and diluted with ether (1 L). The ethereal solution was transferred to a separation funnel and washed with 1M sodium sulfite (2 (500 mL), water (1 (500 mL), and brine (1 (500 mL). The organic layer was dried over MgSO4, filtered, and concentrated in vacuo to afford an oil. Ice cold pentane (50 mL) was then added to the crude product, and the mixture was stirred vigorously. After 20 min, a fine white precipitate formed, which was filtered and washed with pentane (20 mL) and then air dried under a gentle vacuum to afford (4S)-2-bromobicyclo[2.2.1]heptane-1-carboxylic acid (100.2 g, 457 mmol) as a white solid material.

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