m-Chloroperbenzoic acid → HCID 67374942, compound

Participants

Reaction Conditions

Reaction Steps

Dibenzyl N,N-diisopropylphosphoramidite (0.252 mL, 0.751 mmol) was added to a stirred solution of 1H-tetrazole (3 wt % in CH3CN) (4.40 mL, 1.502 mmol) and methyl 2-(acetyloxy)-5-(3-hydroxypropyl)-3-methylbenzoate (100 mg, 0.376 mmol) in dry CH2Cl2 (4.50 mL) at 25° C. under N2. The reaction was stirred for 2 h at 25° C. After this time another 0.5 eq dibenzyl N,N-diisopropylphosphoramidite was added and the reaction was stirred for 30 min. The reaction mixture was cooled to 0° C. and a solution of 3-chloroperoxybenzoic acid (337 mg, 1.502 mmol) in dry CH2Cl2 (3.00 mL) was added via cannula. After 30 min another 1 eq 3-chloroperoxybenzoic acid was added and the reaction was stirred at 0° C. After 30 min the reaction was diluted with EtOAc (30 mL) and washed with successive portions of saturated Na2SO3 (20 mL) and saturated NaHCO3 (20 mL), dried (MgSO4) and concentrated in vacuo to give the crude product. This was purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/min, 100% hexanes for 144 mL, gradient to 60% EtOAc in hexanes over 2394 mL) to afford methyl 2-(acetyloxy)-5-(3-{[bis(benzyloxy)phosphoryl]oxy}propyl)-3-methylbenzoate, as a colorless oil. LCMS calc.=527.2; found=527.0 (M+H)+. 1H NMR (500 MHz, CHCl3): δ 7.62 (d, J=2.2 Hz, 1 H); 7.36-7.31 (m, 10 H); 7.18 (d, J=2.2 Hz, 1 H); 5.11-4.98 (m, 4 H); 4.00 (q, J=6.6 Hz, 2 H); 3.84 (s, 3 H); 2.61 (t, J=7.8 Hz, 2 H); 2.36 (s, 3 H); 2.17 (s, 3 H); 1.93-1.85 (m, 2 H).

Provenance & Evidence