Dimethylformamide → 4-Vinylbenzaldehyde

温度

20 °C

A solution of 17.06 mL (0.220 moles) of anhydrous N,N′-dimethylformamide in 100 mL of anhydrous tetrahydrofuran was cannula transferred into the 125 mL addition funnel and then added dropwise over a period of 1 hour to the previously prepared solution of p-vinylphenylmagnesium chloride (0.199 moles). The temperature was maintained at 20° C. during the addition (higher temperatures resulted in polymer formation and lower yields). The reaction mixture was stirred for 2 hours and then allowed to remain overnight under a nitrogen atmosphere. The reaction mixture was quenched with 200 mL saturated aqueous ammonium chloride solution causing an initial exotherm (up to 45° C.) and then the precipitation of a voluminous “gelatinous” white solid (magnesium hydroxides). The resultant emulsion was broken by centrifuging aliquots of the mixture at 4000 rpm for 3 minutes and the resultant clarified two phase mixture poured into a 500 mL separating funnel and the organic layer partitioned and collected. The remaining aqueous layer was extracted twice with 100 mL of Et2O; the organic extracts were then combined and dried over anhydrous MgSO4. The drying mixture was filtered and the collected solid washed with 2×50 mL portions of Et2O. The filtrate and washings were combined and the solvent was stripped off in vacuo using a rotary evaporator and the residue was distilled in vacuo in the presence of a heaped spatula measure of phenothiazine with two fractions coming over: Fraction 1 (53° C. at 0.425 torr; v. pale yellow liquid), Fraction 2 (48-50° C. at 0.350 torr; v. pale yellow liquid). Fraction 1 was discarded and fraction 2 retained and a yield taken. Yield: 18.325 g (70%, very pale yellow liquid). 1H NMR (CDCl3) δ 5.46 (d, 1H, ═C—H), 5.93 (d, 1H, ═C—H), 6.79 (dd, 1H, ═C—H), 7.57 (d, 2H, ArH), 7.86 (d, 2H, ArH), 10.01 (s, 1H, —CH═O).

1. additiontransferred into the 125 mL addition funnel
2. waitto remain overnight under a nitrogen atmosphere
3. customThe reaction mixture was quenched with 200 mL saturated aqueous ammonium chloride solution
4. customup to 45° C.
5. customthe precipitation of a voluminous “gelatinous” white solid (magnesium hydroxides)
6. waitThe resultant emulsion was broken by centrifuging aliquots of the mixture at 4000 rpm for 3 minutes
7. additionpoured into a 500 mL
8. customseparating funnel
9. customthe organic layer partitioned
10. customcollected
11. extractionThe remaining aqueous layer was extracted twice with 100 mL of Et2O
12. dry with materialdried over anhydrous MgSO4
13. filtrationThe drying mixture was filtered
14. washthe collected solid washed with 2×50 mL portions of Et2O
15. customa rotary evaporator
16. distillationthe residue was distilled in vacuo in the presence of a heaped spatula measure of phenothiazine with two fractions
17. customFraction 1 (53° C. at 0.425 torr; v. pale yellow liquid), Fraction 2 (48-50° C. at 0.350 torr; v. pale yellow liquid)

ORDレコード

ord-879d599bbba9436d978272ee4aa53ea4

出典データセット

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09115063B2