A mixture of [1-(4-Chloro-phenyl)-cyclobutyl]-carbamic acid tert-butyl ester 1-1 (prepared according to WO2008/070016; 1.57 g, 5.6 mmol), Zn(CN)2 (395 mg, 3.37 mmol), Pd2(dba)3 (257 mg, 0.28 mmol), dppf (311 mg, 0.56 mmol), Zinc powder (219 mg, 3.37 mmol) and 20 mL of DMF was heated to 100.deg.C for 2 hrs under nitrogen atmosphere. After cooling to room temperature, the mixture was poured into water and extracted with EA for three times. The combined EA layer was washed with water, brine and concentrated to give a residue, which was purified by silica gel chromatography eluting with EA/PE (3/1) to give 1.23 g of compound 1-2. MS (ESI) m/e (M+H+): observed=273.2, calculated=273.2.
