Electric Literature of 17715-70-7,Some common heterocyclic compound, 17715-70-7, name is 2,4-Dimethoxy-1-fluorobenzene, molecular formula is C8H9FO2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Preparation 29 6-Fluoro-7-hydroxychroman-4-one A mixture of 1,3-dimethoxybenzene (3.80 mL, 29.0 mmol) and N-fluorodibenzenesulfonamide (4.21 g, 29.21 mmol) was heated at 60 C. overnight. The mixture was cooled and flash chromatographed on silica gel (2*5 inches packed in hexane) with elution proceeding as follows: 3% ethyl acetate/hexane (1000 mL), discarded forerun; 3% ethyl acetate/hexane (1000 mL), 2.69 g of a 2:1 mixture of 2,4-dimethoxyfluorobenzene and starting material which was carried directly into the next step. The product of the above reaction was combined with acetic acid (11 mL) and 48% HBr (11 mL) and refluxed 3 h. The reaction was concentrated and flash chromatographed on silica gel (2*5 inches packed in hexane) with elution proceeding as follows: 10% ethyl acetate/hexane (2000 mL), 0.95 g (43%) of 2,4-dihydroxyfluorobenzene as a waxy white solid which was used without purification. A mixture of 2,4-dihydroxyfluorobenzene (0.15 g, 1.17 mmol), 3-chloropropionic acid (0.13 g, 1.20 mmol) and trifluoromethanesulfonic acid (1 mL) were heated to 80 C. for 3 h. The reaction was poured into water and extracted with ether (3*). The combined organic phase was washed with water and brine, dried over magnesium sulfate, and concentrated to give 2,4-dihydroxy-5-fluoro-beta-chloropropiophenone as a red solid which had: NMR delta 7.37 (d, J=10.8 Hz, 1 H), 6.54 (d, J=7.7 Hz, 1 H), 3.87 (t, J=6.8 Hz, 2 H) 3.33 (t, J=6.8 Hz, 2 H). This product still contained some residual 3-chloropropionic acid but was suitable for use in the next reaction.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,4-Dimethoxy-1-fluorobenzene, its application will become more common.
Reference:
Patent; Pfizer Inc.; US6046213; (2000); A;,
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