2-Furaldehyde semicarbazone preparation

Repeat the preceding experiment, but use 0.3 g of 2-furaldehyde semicarbazone (prepared in Part B) and 0.3 mL of cyclohexanone in place of the cyclohexanone semicarbazone and 2-furaldehyde. 

Place 0.3 g of cyclohexanone semicarbazone. prepared in Part A. 0.3 mL of 2-furaldehyde, 2 ml of 95% ethanol, and 10 mL of water in a 25-mL Erlen-meyer flask. Warm the mixture until a homogeneous solution is obtained (about 1 or 2 min should suffice), and continue warming for an additional 3 min. Cool the mixture to room temperature and then place it in an ice-water bath. Collect the crystals on a filter, and wash them with 2-3 mL of cold water. Thoroughly air-dry the crystals and determine their weight and melting point. 

Nitro-2-furaldehyde (5-nitrofurfural), mp 36°C, is prepared by the nitration of 2-fliraldehyde. Some of its derivatives are bacteriostatic and bacteriocidal, e.g. the semicarbazone (Nitrofural), and are used to combat infectious diseases. 

For best results, the 2-furaldehyde should be freshly distilled immediately before use. Prepare the semicarbazone of 2-furaldehyde by following the procedure of Part A exactly, except use 0.4 mL of 2-furaldehyde instead of 0.5 mL of cyclohexanone. Recrystallization of the product is unnecessary. Obtain IR and NMR spectra of your starting material and product. Compare your spectra with those of authentic samples (Figs. 13.7-13.10). 

---