Tricyclohexylphosphine → 3-benzenesulfonyl-3H-indene-1-carboxylic acid ethyl ester

Temperatur

0 °C

A solution of tricyclohexylphophine (46 mg, 0.164 mmol) in tetrahydrofuran (2.5 mL) under nitrogen was charged with palladium (II) acetate (24.5mg, 0.109 mmol). The reaction mixture was stirred for 45 minutes, then cooled to 0° C. and charged with sodium tert-butoxide (270 mg, 2.73 mmol). After 5 minutes a solution of β-ethoxyacrylic acid ethyl ester (158 μL, 1.09 mmol) and 2-bromobenzyl phenyl sulfone (340 mg, 1.09 mmol) in tetrahydrofuran (2.5 mL) was added dropwise over 2 minutes. Upon complete addition the reaction was warmed to room temperature and then heated to 60° C. for 2 hours. The reaction was cooled to room temperature, then diluted with methyl tert-butyl ether (25 mL) and poured into aqueous potassium dihydrogen phosphate (0.25 M, 25 mL), pH=7. The aqueous layer was separated and saturated by addition of solid sodium chloride and extracted with ethyl acetate (2×50 mL). The organic layer was separated and washed twice with aqueous saturated sodium chloride (2×30 mL), dried over sodium sulfate, filtered and concentrated in vacuo affording 3-benzenesulfonyl-3H-indene-1-carboxylic acid ethyl ester as a light orange oil (304 mg, 0.925 mmol, 85%). 1H NMR (400 MHz, CDCl3) δ 7.88–7.86 (m, 1H), 7.75–7.72 (m, 1H), 7.49–7.43 (m, 3H), 7.36–7.32 (m, 2H), 7.27–7.25 (m, 3H), 5.15 (d, 1H, J=2.1), 4.27 (q, 2H, J=7.1), 1.34 (t, 3H, J=7.1); IR (ATR, neat) 1709, 1649, 1463, 1444, 1314, 1271, 1247, 1188, 1133, 1081, 1044, 773, 752, 722, 686, 575, 528.

1. additionUpon complete addition the reaction
2. temperaturewas warmed to room temperature
3. temperatureheated to 60° C. for 2 hours
4. temperatureThe reaction was cooled to room temperature
5. customThe aqueous layer was separated and saturated by addition of solid sodium chloride
6. extractionextracted with ethyl acetate (2×50 mL)
7. customThe organic layer was separated
8. washwashed twice with aqueous saturated sodium chloride (2×30 mL)
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated in vacuo

ORD-Eintrag

ord-9aeb12b8ac724711b637d517d0227baf

Quelldatensatz

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07091372B2