Separation of rosin acids by molecular recognition: crystal structure of the complex of neoabietic acid with 2-amino-6-methyl-pyridine

Neoabietic acid has been separated from gum rosin mixture by the aid of molecular recognition using 2-amino-6-methyl-pyridine as recognition reagent. The complex of neoabietic acid with 2-amino-6-methy-pyridine crystallizes from ether solution in the monoclinic; space group P2(1) with cell parameters of a = 7.370(1), b = 8.692(1), c = 18.365(2) Angstrom, beta = 92.53(1)degrees, Tr = 1175.3(2) Angstrom (3) and Z = 2. X-ray structure analysis shows that an extensive H-bonding network exists between neoabietic acid and amino(methyl)pyridine, which is considered as one of the factors resulting in successfully separating the neoabietic acid from the gum rosin mixture.