Methyl 2-Benzyl-3-phenyl-2-(phenylsulfonyl)propanoate

The product 2 was prepared from methyl phenylsulfonyl acetate in situ by the solid-liquid PTC conditions without solvent [1,2]. To ester 1 (0.535 g, 2.5 mmol), was added benzyl chloride (0.791 g, 6.25 mmol), ^tBuOK (0.701 g, 6.25 mmol) and 10 % of TBAB (tetrabutylammonium bromide) phase transfer catalyst (80 mg, 0.25 mmol). The reaction was carried out under ambient temperature with magnetic agitation during 1 min. An approximate temperature of 95°C was measured at the end of the reaction. The mixture was allowed to cool to ambient temperature. After dilution with ethyl acetate (30 ml) and subsequent filtration through Florisil^TM, the organic product was analysed by GC (using an internal standard) and purified by chromatography on silica gel (pentane: ethyl acetate, 95 : 5), yield: 88 % of isolated product 2.

¹H NMR (CDCl₃): 3.48 (s, 4H); 3.68 (s, 3H); 7.10-7.23 (m, 10H); 7.48-7.82 (m, 5H).

¹³C NMR (CDCl₃): 165 (ester).

IR (Nujol): 1740 (CO₂); 1310 and 1140 cm^-1 (SO2).

MS (IC-NH₃, m / z): 412 (M⁺ + 18) / 29.3 %; 272 (M⁺ - PhSO₂ + 18) / 100%.