Pyridine → 4-Methoxy cinnamic acid

Participants

Reaction Steps

4.3 g of dl-α-tocopherol (0.010 mol) and 1.34 g of pyridine (0.017 mol) are placed in 20 ml of CH2Cl2 while gassing with argon in a 100 ml 4-necked sulphonation flask provided with a temperature, a 20 ml dropping funnel, a magnetic stirrer and a reflux condenser. A solution of 0.95 g of 4-methoxycinnamic acid chloride (0.015 mol) in 15 ml of CH2Cl2 is added dropwise within 10 minutes. The reaction mixture is heated to reflux temperature for 3 hours. The solution is washed in succession with 10 ml of water, 10 ml of 5% HCl and 10 ml of 5% NaHCO3. After drying (Na2SO4) the solvent is concentrated on a rotary evaporator. The crude product (6.3 g) is chromatographed (toluene) on 150 g of silica gel (0.040-0.063 mm) under 0.5 bar pressure. There are obtained 5.2 g of yellowish d,l-α-tocopherol ester of p-methoxycinnamic acid (yield 88%).

Provenance & Evidence