Acetic Anhydride → HCID 69981834, compound

Participants

Reaction Steps

An ice cold, stirred mixture of the product from Step 7 (6.39 g, 0.0125 mol) and pyridine (75 ml), under nitrogen is treated, dropwise during 10 min, with acetic anhydride (24 ml). The mixture is kept in the ice bath for 20 min and at ambient temperature for 2 h. It is then concentrated in vacuo. The residue is mixed with ethyl acetate, washed with dilute sodium bicarbonate, water, and brine, dried (Na2SO4) and concentrated. Chromatography of the residue on silica gel with mixtures of MeOH—CH2Cl2 containing 2.5 −5% MeOH gave the titled product: MS (ES) m/z 554 (M+H+), 576 (M+Na+); 1H NMR (300 MHz, CDCl3) δ−0.12 (s, 3H), −0.07 (s, 3H), 0.75 (s, 9H), 2.01 (s, 3H), 3.08 (m, 1H), 3.23 (m, 1H), 3.58 (m, 2H), 3.73 (m, 3H), 4.00 (m, 1H), 4.50 (broad s, 1H), 4.73 (m, 1H), 5.27 (m, 2H), 6.22 (broad s, 1H), 7.08 (m, 1H), 7.37 (m, 6H), 7.79 (broad s, 1H).

Provenance & Evidence