2 DIASTEREOMERS OF NYLAMINO)-ALPHA-METHYLPHENETHYL]-METHYLAMINO]-N,N-DIMETHYLACETAMIDE

The structures of two diastereomers ((1R,2R) and (1R,2S)) of the title compound have been determined. The molecular conformation of the (1R, 2R) isomer is heavily influenced by strong intramolecular hydrogen bon ding between the secondary and tertiary amine groups (N(1)... N(2) 2.6 29(8) Angstrom; N(4)... N(5) 2.628(8) Angstrom). In the (1R,2S) isomer no intramolecular interaction is observed, but somewhat weaker interm olecular hydrogen bonding does occur between the secondary amine and t he carbonyl group of a neighboring molecule (N(1)... O(1) 2.960(6) Ang strom) related by a 2(1) screw operation along the a-axis (x 1/4 0). N o close intermolecular contacts are observed for the (1R,2R) isomer. C rystal data for (1R,2R): monoclinic, P2(1) (No. 4), a 18.588(5), b = 1 6.743(4), c = 6.062(1)Angstrom, beta = 97.26(2)degrees, V = 1871.5(8) Angstrom(3), Z = 4, D-calc = 1.16 g/cm(3). Crystal data for (1R,2S): o rthorhombic, P2(1)2(1)2(1), (No. 19), a = 8.008(2), b = 9.985(3), c = 23.458(5)Angstrom, V = 1875.8(6) Angstrom(3), Z = 4, D-calc = 1.15 g/c m(3).