Synthesis and Crystal Structure of Ethyl 2-amino-7,7-dimethyl-4-(4′-fluorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzopyran-2-carboxylate in Water

The title compound (C20H22FNO4) has been synthesized by the reaction of ethyl 4fluorobenzylidenecyanoacetate with 5,5dimethyl1,3cyclohexaneclione in water in the presence of triethylbenzylammonium chloride (TEBA),and its structure was determined by monocrystalline Xray diffraction. The crystal is triclinic, space group P-1 with a=0.826 6(1) nm, b=0.977 3(1) nm, c=1.237 5(2) nm, α=8140(1)°, β=7341(1)°, γ=8215(1)°,Z=2,V=0.942 6(2) nm3,Mr=35939,Dc=1266 g·mm-1,μ (Mo Kα)=0094 mm-1, F(000)=380, The structure was solved by direct methods and refined by the fullmatrix method of leastsquares to the final R=0040 3 and Rw=0105 7. Xray analysis reveals that the dihedral angle between plane 1 (phenyl ring) and plane 2 (C(8), C(13), C(14), C(15)) is 8956°, between plane 2 and plane 3 (C(8), C(9), C(10), C(12), C(13)) is 1337°,between plane 1 and plane 3 is 10270°,the pyran cycle and the sixmembered cycle fused with it are of boat and envelope configurations in the structure respectively.