Synthetic Route of 21120-91-2, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 21120-91-2 as follows.
In a 250 ml three necked round bottom flask equipped with a polytetraflouroethylene (Teflon polymer, Dupont, Wilmington, Del.) coated magnetic stir bar, potassium hydroxide (1.38 g, 1 eq) was dissolved in water (6.83 g). Then 4-acetoxy styrene (4 g, 1 eq) was added dropwise at room temperature, and the solution turned from colorless to pale orange. Potassium carbonate (6.82 g, 2 eq) was added portionwise, and the solution was stirred for one hour. The flask was equipped with a reflux condenser, then 1-bromobenzocyclobutene (4.06 g, 1 eq) was added dropwise in DMF (41 ml). The solution was then heated to 70 C. and allowed to reflux overnight. To the reaction was added water (50 ml) and ethyl acetate (50 ml). The aqueous residue was extracted four times with ethyl acetate (100 ml). The combined organics were extracted with sodium bicarbonate solution (1×100 ml), lithium chloride aqueous solution (1×100 ml) and brine (2×100 ml). The organics were dried over sodium sulfate, filtered and concentrated in vacuo to give the product as a of white solid (3.36 g, 68% yield). Melting point 54-60 C. 1H NMR (600 MHz, Chloroform-d) delta 7.39 (d, J=8.6 Hz, 2H), 7.34 (td, J=7.3, 1.5 Hiz, 1H), 7.31-7.24 (m, 2H), 7.21-7.18 (m, 1H), 6.98 (d, J=8.6 Hz, 2H), 6.69 (dd, J=17.6, 10.9 Hz, 1H), 5.70 (dd, J=4.3, 1.9 Hz, 1H), 5.64 (dd, J=17.6, 0.9 Hz, 1H), 5.15 (dd, J=10.9, 0.9 Hz, 1H), 3.73 (dd, J=14.2, 4.3 Hz, 1H), 3.31 (d, J=14.2 Hz, 1H). 13C NMR (151 MHz, Chloroform-d) delta 157.79, 144.62, 142.57, 136.20, 130.87, 129.93, 127.50, 127.43, 123.48, 123.04, 115.06, 111.80, 74.28, 39.45. Yield from the above example was good and the resulting monomer was a stable solid which has a desirable ring opening cure temperature of 184 C.
According to the analysis of related databases, 21120-91-2, the application of this compound in the production field has become more and more popular.
Reference:
Patent; Rohm and Haas Electronic Materials LLC; Hayes, Colin; Gallagher, Michael K.; Riener, Michelle; (10 pag.)US2019/169327; (2019); A1;,
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