PIPERONYL ALCOHOL AND ESTERS

Synthesis Example 1 Synthesis of piperonyl alcohol  http://www.google.com/patents/WO2004071481A1?cl=en

In a 500-ml autoclave were placed 90 g (0.60 mol) of heliotropin, 270 ml of 1-propanol and 3 g of a Raney nickel catalyst (Raney-Ni) . Hydrogen gas was filled therein up to 4 MPa. The autoclave contents were stirred at 90 °C for about 10 hours. The reaction mixture was filtered and the filtrate was concentrated. The resulting residue was puri¬ fied by silica gel column chromatography (hexane: ethyl ace¬ tate = 20:1) to obtain 27.6 g of piperonyl alcohol as white crystals (yield: 30.3%, G.C. purity: 98.4%) m.p.: 49-51°C ^XH-NMR (CDCI3, δ ppm) 1.86 (s,lH), 4.56 (s,2H), 5.95 (s,2H), 6.77-6.79 (m,2H), 6.85 (s,lH) MS: 152 (M⁺) , 135, 123, 105, 93, 77, 65, 51, 39, 29 IR and NMR spectroscopy was used in order to determine the purity of the intermediate. IR spectroscopy showed a peak at 2986.82 cm-1 which correlated to a C-H bond which should be expected in any organic molecule, but the peaks that were specifically consistent with its structure were at 1490.07 cm-1, 1275.61 cm-1, and 810.03 cm-1. These peaks correlated to a C=C aromatic bond, C-O alcohol bond, and C-H aromatic bond.       NMR Spectroscopic Data-

 

      Synthesis of piperonyl esters  

The piperonyl alcohol produced in Synthesis Example 1 was reacted with a carboxylic acid anhydride or a carbox¬ ylic acid chloride in the presence of a base. The reaction mixture was purified with distilled water or by silica gel column chromatography to produce piperonyl esters having different substituents R₂.