We initially explored the reaction condition of benzaldehyde (1 equiv.) with hydroxylamine hydrochloride (1.5 equiv.) and triphosgene (0.2 equiv.) at 60 °C with acetonitrile as the solvent in the yield of 97 (Table ). To our delight, the desired product of acetophenone, acetanilide was obtained with a similar method in 81% yield at 80 °C (Table ). None of the other solvents screened were superior to acetonitrile. We investigated the reaction in the absence of triphosgene, according to benzaldehyde, and the reaction did fully convert but little proceed further after producing the oxime. Besides, acetophenone has a similar pattern but lower conversion. To improve the conversion and selectivity of the aldehydes and ketones in the tandem reaction, we took the approach, which adds hydroxylamine hydrochloride and triphosgene by steps, and we were pleased to observe the desired nitrile and acetanilide product in 99% and 90%, respectively. (refer to ESI † for more details). Table . Variation of standard condition for the transformation of benzaldehyde to benzonitrile. *All reactions were performed on 0.5 mmol scale at 80 °C for 6 h. a Determined by GC with the GC datas of 1d-10, M1d-10 and P1d-10 as reference.