Dimethylformamide → 3-{[tert-Butyl(dimethyl)silyl]oxy}-5-ethyl-2-fluorobenzaldehyde

Participants

Reaction Conditions

Reaction Steps

A mixture of Intermediate 368.1 (7.5 g, 29.5 mmol) and PMDTA (7 mL) in THF (50 mL) was cooled to −78° C. 1.6 M n-butyl lithium (21 mL, 32.4 mmol) was added dropwise and the mixture was stirred for 40 min at −60° C. The mixture was cooled to −78° C. and added DMF (4.6 mL, 59 mmol) before allowing the mixture to warm to 23° C. The mixture was quenched with aqueous NH4Cl and extracted with EtOAc (3×50 mL). The organic layer was washed with H2O and brine, passed through a 2″ SiO2 plug eluting with EtOAc/Hex (95/5), dried (Na2SO4) and concentrated to afford 7 g of Intermediate 368.2. 1H NMR (400 MHz, CDCl3) δ ppm 0.21 (s, 6H) 0.97-1.03 (m, 9H) 1.21 (t, J=7.69 Hz, 3H) 2.59 (q, J=7.76 Hz, 2H) 6.99 (dd, J=8.13, 2.42 Hz, 1H) 7.20-7.29 (m, 1H) 10.30 (s, 1H).

Provenance & Evidence