CRYSTAL-STRUCTURE OF ETHYL 4-METHYLTHIO-3-PHENYL-2-THIOXO-2,3-DIHYDRO-1,3-OXAZOLE-5-CARBOXYLATE

The title compound C13H13NO3S2 crystallizes in the triclinic space group P $($) over bar$$ 1 (Z = 2) with lattice constants a = 8.382(2), b = 10.042(2), c = 10.134(2) Angstrom, alpha = 119.35(1)degrees, beta = 101.40(1)degrees and gamma = 90.54(1)degrees. The interplanar angle between the least squares planes of the 1,3-oxazoline ring and the phenyl ring amounts to 90.2 degrees, thus hindering conjugation between the benzene and heterocyclic system. The observed bond parameters of the five-membered heterocycle suggest a significant contribution from a zwitterionic dipolar limiting structure [38.7(5)%] to the description of this ring system. The particular contributions of the resonance structures were estimated by calculations using the HOSE model on the base of the observed bond lengths.