N-bromobutanimide → 6-Bromo-7-fluorochroman

HRID 1912622Notes

Reaction equation

HRID 1912622 reaction equation
[F:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1.C1C(=O)N([Br:19])C(=O)C1>C(#N)C.O>[Br:19][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:2]=1[F:1])[O:9][CH2:8][CH2:7][CH2:6]2

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 224048067-Fluorochroman

Product 1

HCID 712090886-Bromo-7-fluorochroman

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Procedure

A solution of 7-fluorochroman (4.42 g, 29.0 mmol) in acetonitrile (40 mL) at 0° C. was treated with NBS ((5.16 g, 29 mmol)) and the mixture was stirred at ambient temperature for 2 hours. The reaction was diluted with water, stirred for 1 hour and then extracted with ethyl acetate, dried over sodium sulfte and concentrated under reduced pressure give a 6-bromo-7-fluorochroman as the major product in a 3:1 mixture of regioisomers as a colorless oil (4.05 g). This material was used in the next step without further purification. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm=7.19 (d, J=7.8 Hz, 1 H), 6.59 (d, J=10.0 Hz, 1 H), 4.19-4.16 (m, 2 H), 2.74 (t, J=6.5 Hz, 2 H), 2.04-1.95 (m, 2 H); LCMS (m/z) ES+=230 (M−1).

Workup

  1. stirringstirred for 1 hour
  2. extractionextracted with ethyl acetate
  3. dry with materialdried over sodium sulfte
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-bf5347c3ef2c46ea893653f4fc893c7b
Source dataset
uspto-grants-2013_12
Patent number
US08609653B2

Reaction notes

Loading…