Methyl phenyl sulfone → 3-((Phenylsulfonyl)methylene)oxetane

A solution of BuLi (2.5 M in hexanes, 22.5 mL, 56.3 mmol) was added over 10 min to a solution of methylphenylsulfone (4.00 g, 25.6 mmol) in THF (70 mL) at 0° C. The solution went from clear to light green to a heterogeneous yellow suspension. The mixture was stirred for 30 min at 0° C. and then chlorodiethylphosphonate (4.46 mL, 30.7 mmol) was added dropwise and the stirring was continued for 30 min, at which point the solution turned clear orange. The reaction mixture was then cooled to −78° C. and oxetan-3-one (1.85 g, 25.6 mmol) was added in THF (3 mL). The reaction mixture turned pale brown/yellow in color. After stirring for another 1.5 h, the reaction mixture was filtered through a plug of silica gel. The filtrate was triturated with solid NH4Cl until pH reached 7. The mixture was then filtered and the filtrate was concentrated. The residue was purified by silica gel chromatography (0-60% EtOAc/heptane) to provide 3-((phenylsulfonyl)methylene)oxetane. 1H NMR (400 MHz, CD2Cl2) δ ppm 7.86-7.99 (m, 2 H) 7.68-7.77 (m, 1 H) 7.57-7.68 (m, 2 H) 6.18 (t, J=2.40 Hz, 1 H) 5.59-5.70 (m, 2 H) 5.30 (td, J=3.41, 2.27 Hz, 2 H)

1. waitthe stirring was continued for 30 min, at which point
2. temperatureThe reaction mixture was then cooled to −78° C.
3. stirringAfter stirring for another 1.5 h
4. filtrationthe reaction mixture was filtered through a plug of silica gel
5. customThe filtrate was triturated with solid NH4Cl until pH
6. filtrationThe mixture was then filtered
7. concentrationthe filtrate was concentrated
8. customThe residue was purified by silica gel chromatography (0-60% EtOAc/heptane)

ORD-Eintrag

ord-e2a61aad2c30423b800fc11c72aa020a

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08846656B2