n-Butyl nitrite; phenyl silane; N,N'-bis(2-ethoxycarbonyl-3-oxobutylidene)ethylenediaminatocobalt(II) complex in tetrahydrofuran 48 h; Ambient temperature;

(i) H2SO4, (ii) NH2OH*HCl, aq. NaOAc; Multistep reaction;