4-Nitrobenzaldehyde → 1-(4-Nitrophenyl)prop-2-en-1-ol

p-Nitrobenzaldehyde (1 g, 6.6 mMoles) and 30 ml of dry tetrahydrofuran (THF) was stirred at 0° C. in a septum sealed flask equipped with a pressure equalizing funnel. After purging with dry nitrogen, 7 ml of 1M vinyl magnesium bromide in THF was added dropwise under a nitrogen atmosphere. After addition of the Grignard reagent, the reaction was allowed to stir at room temperature for 30 min. The bulk of the THF was removed under vacuum and the reaction was quenched by pouring it into a slurry containing 200 ml of water, crushed ice and 100 ml of ether. The final pH of the slurry was adjusted to near neutral by dropwise addition of 2M sulfuric acid. The product was extracted with ether and the pooled extracts were washed twice with 30 ml of water and twice with 30 ml of saturated NaCl. Ether was removed under vacuum yielding a dense yellow oil which was chromatographed on preparative silica TLC plates using toluene: acetonitrile 10:1 (v/v) as running solvent. Elution of the product from silica with methanol yielded 700 mg of semi-crystalline 1-(4'-nitrophenyl)-2-propen-1-ol. Recrystallization from toluene and then ethanol gave needles of pure product. IR: (chloroform) (cm-1) --OH, 3600, 1040; intermolecular --OH, --C=CH2, 3020, 2870, 985, 935 aromatic, 1607, 858; --NO2, 1510, 1350, 872. NMR: δ(p.p.m.) ([2H]chloroform), 2.2 (1H, broad s, --OH, D2O exchangeable), 5.26 (1H, d, J2,3 cis 10.6 Hz, J3,3 gem 1 Hz, --C=CH2), 5.32 (1H, broad m, --CH=C), 5.42 (1H, d, J2,3 trans 17.2 Hz, J3,3 gem 1 Hz --C=CH2), 6.0 (1H, m, C--CH=C), 7.4 (2H, d, J 9 Hz, aromatic), 8.21 (2H, d, J 9 Hz, aromatic). UVmax 272 nm, ε= 10,500 M-1 cm-1.; Mp.=55° C.

1. customsealed flask
2. customequipped with a pressure
3. customAfter purging with dry nitrogen, 7 ml of 1M vinyl magnesium bromide in THF
4. additionwas added dropwise under a nitrogen atmosphere
5. additionAfter addition of the Grignard reagent
6. customThe bulk of the THF was removed under vacuum
7. customthe reaction was quenched
8. additionby pouring it into a slurry
9. additioncontaining 200 ml of water
10. customcrushed ice and 100 ml of ether
11. additionto near neutral by dropwise addition of 2M sulfuric acid
12. extractionThe product was extracted with ether
13. washthe pooled extracts were washed twice with 30 ml of water and twice with 30 ml of saturated NaCl
14. customEther was removed under vacuum
15. customyielding a dense yellow oil which
16. customwas chromatographed on preparative silica TLC plates
17. washElution of the product from silica with methanol

ORD record

ord-4088e9afc9454f05845568737cc2a8bc

Source dataset

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05258296