Saturated anhydrous ethanolic ammonia

Both anhydrous and hydrated sodium or potassium sulfide in ethanol have been used in the synthesis of thietanes. A common procedure is to use a solution of sodium or potassium hydroxide saturated with hydrogen sulfide. Liquid ammonia has been used as a solvent for the preparation of thietane (32%) from sodium sulfide and 1,3-dibromopropane. Phase-transfer catalysis has been used to good effect.A variation in which l,3-dichloro-3-methylbutane 3 is treated with aluminium chloride and hydrogen sulfide followed by aqueous sodium hydroxide gave 2,2-dimethylthietane 4 in 90% yield. An intermediate aluminium chloride-alkene complex, 5 or 6, was proposed. 

Spiro[5.5]undecan-3-one (33.2 g, 0.2 mol) and 47.5 g ethyl cyanoacetate (0.42 mol) were placed in a 500-mL thick-walled flask. The mixture was cooled to 0°C, and 100 mL ethanol saturated with anhydrous ammonia at 0°C was added. A stopper was wedged and the mixture was stored at 0-5°C for 1 week. The precipitated ammonium salt of the Guareschi imide was filtered, dissolved in boiling water. Altered, and acidified with HCI. The Guareschi imide was filtered, washed with water, and dried. It melted at 230-233°C and 232-233°C after recrystaUization from alcohol-water. l,5-Dicyano-3-azadispiro[5.2.5.2] hexadecane-2,4-dione (24 g) was obtained, in a yield of 40%. 

Reagents and Equipment. Weigh and place 40 mg (0.15 mmol) of the frans-2-(4-nitrophenyl)-3-benzoylaziridine synthesized in Experiment [F3] in a 15-mL screwcapped centrifuge tube containing a magnetic spin vane. Dissolve the aziridine (20 xL of EtOH/mg of aziridine) and benzaldehyde (140 xL, 1.37 mmol) in 800 xL of absolute ethanol.To this solution add 14 mg (0.14 mmol) of ammonium bromide (0.35 mg of NH4Br/mg of aziridine). Stir this mixture for 1 min and saturate the system with anhydrous ammonia (NH3) in the hood (see your instructor for directions on this addition). 

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