2- Furfuryl mercaptan

Caution The following operations should be carried out in an effective hood (Note 1). 

In a 3-1. round-bottomed flask are placed 380 g. (5 moles) of thiourea (Note 2), 500 ml. of water, and 400 ml. of concentrated hydrochloric acid (12.5 N) (Note 3). The solid is dissolved by gentle heating, and the solution is cooled to 30°. Furfuryl alcohol (490 g., 434 ml., 5 moles) (Note 4) is added to the reaction mixture. The reaction, which usually commences spontaneously within a few minutes (Note 5), is strongly exothermic and should be controlled by suitable cooling writh tap water so as to hold the temperature near 60° (Note 6). When the reaction subsides, cooling is discontinued and the clear, dark green solution is allowed to stand at room temperature for 12 hours. 

A solution of 225 g. of sodium hydroxide (Note 3) in 250 ml. of water is poured into the reaction mixture. A heavy brown oil separates, consisting of S-2-furfurylisothiourea, which has already partially decomposed to 2-furfuryl mercaptan. The flask is quickly fitted with a steam-inlet tube and condenser. Steam distillation is continued as long as the distillate contains oily drops. The mercaptan is separated from the aqueous phase by means of a separatory funnel (Notes 7 and 8). The product is dried with calcium chloride yield, 313-340 g. (55-60%). The 2-furfuryl mercaptan so obtained is of a high degree of purity (Note 9) but can be distilled without decomposition in a nitrogen atmosphere b.p. 160°/759 mm., 84°/65 mm., n 1.533. 

The odor of the mercaptan is extremely disagreeable, and the substance in high concentration causes headache. An effective hood is absolutely essential. 

The checkers employed practical-grade thiourea obtained from Matheson, Coleman and Bell, East Rutherford, New Jersey. 

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Furfuryl chloride, 35, 68 2-Furfuryl disulfide, 35, 68 S-2-Furfurylisothiourea, 35, 67 2-Furfuryl mercaptan, 35, 66 2-Furoic acid, 36, 36 Furylacrylic acid, 33, 25 Fusion, caustic, of vanillin, 30, 103... 

CAS 98-02-2 EINECS/ELINCS 202-628-2 UN 1228 (DOT) UN 3071 (DOT) FEMA 2493 Synonyms 2-Furanmethanethiol Furfural mercaptan 2-Furfuryl mercaptan a-Furfuryl mercaptan a-Furfuryl mercaptan Furfuryl thiol 2-Furylmethanethiol 2-Furylmethyl mercaptan Empirical CsHeOS... 

FurFuryl alcohol 202-627-7 Furfural QO Furfural 202-628-2 Furfuryl mercaptan 202-634-5 Benzotrichloride 202-637-1... 

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