To a well-stirred mixture of cyano acid (80 mmol) in alcohol (90 mmol), and acetonitrile (162 mmol) , added sulfuric acid (98%, 94 mmol, 5 mL) at room temperature and temperature maintained between 80-85°C for 16-18h. The reaction mixture was cooled and added to 20% sodium carbonate solution (100 mL). The reaction mass was extracted in CH2Cl2 (50 mL × 2). The combined organic layer was washed with water (100 mL), dried over sodium sufate, and concentrated under reduced pressure to obtain n-Butyl cyanoacetate (85-95%).