Org. Synth. 1927, 7, 50

DOI: 10.15227/orgsyn.007.0050

HYDROGEN CYANIDE (ANHYDROUS)

[ Hydrocyanic acid ]

Submitted by K. Ziegler

Checked by Henry Gilman and L. C. Heckert.

1. Procedure

5-l. round-bottomed flask , set up in a good hood (Note 1) , is fitted with a three-holed rubber stopper that holds two 250-cc. separatory funnels , A and B (Fig. 18). A small funnel F (about 3–4 cm. in diameter) is suspended directly under the outlets of the two separatory funnels and is attached to the rubber stopper by a loop of stiff copper wire. The discharge tube of the funnel is bent in the shape of a U so that its end is about 1 cm. below the top of the funnel. In the third hole of the rubber stopper is inserted an inclined glass tube, C, of about 10-mm. internal bore and approximately 50 cm. long . A mercury safety vent , D, is sealed in the side of this tube. C acts as an air condenser and leads to an empty gas bottle, E, of about 250-cc. capacity and then to three large U-tubes, G, H, and I, filled with anhydrous calcium chloride . The gas bottle and the U-tubes are contained in a water bath , W, warmed to 30–40°. The last calcium chloride tube is fitted with a three-way glass stopcock so that the gaseous anhydrous hydrogen cyanide may be used directly or diverted to an efficient condenser for liquefaction. The condenser is a glass coil of 4–5 mm. bore and about 50 cm. long that is surrounded by ice (Note 2) contained in a percolator arrangement like that described on , set up in a good, is fitted with athat holds, A and B (Fig. 18). A smallis suspended directly under the outlets of the two separatory funnels and is attached to the rubber stopper by a loop of stiff copper wire. The discharge tube of the funnel is bent in the shape of a U so that its end is about 1 cm. below the top of the funnel. In the third hole of the rubber stopper is inserted an. A, D, is sealed in the side of this tube. C acts as anand leads to anand then to. The gas bottle and the U-tubes are contained in a, W, warmed to 30–40°. The lastis fitted with aso that the gaseousmay be used directly or diverted to an efficient condenser for liquefaction. Thethat is surrounded by icecontained in a percolator arrangement like that described on p. 117

Fig. 18.