Calcium thioacetate

Cyclic flve-membered mono- and dltiiioacetab were reduced with calcium in liquid ammonia to give )3-alkoxy- and )3-thioalkoxymercaptans, respectively RCH2OCH2CH2SH and RCHjSCHjCHjSH. Benzaldehyde ethylenedi-thioacetal, on the other hand, gave toluene (75%), and phenylacetaldehyde ethylenedithioacetal gave ethylbenzene (71% yield) [795]. 

Ammonium Carbonate. — On adding 3 cc. of calcium chloride solution to 10 co. of ammonium thioacetate solution, no precipitate, should form, even on warming. 

Cyclization of an aminoaldehyde [as its thioacetal (2.7)] was achieved in high yield and under mild conditions in the presence of mercury(II) chloride and calcium carbonate [3272, 3710]. Heating aminoacetals (review [3326]) such as... 

Mercaptovaleric acid 44 Thioacetic acid (25 g) is added to 2-pentenoic acid (25 g), and next day a crystalline substance (39.5 g m.p. 43-45°) is obtained by distillation at 133-1340/2mm. This acetylthio compound is hydrolysed by treatment with sodium hydroxide (25 g) in water (200 ml) and on the following day the solution is acidified with concentrated sulfuric acid (60 g) in water (60 ml) and extracted with ether. The extracts are dried by calcium chloride, whereafter distillation affords the 2-mercaptovaleric acid, b.p. 108-110°/4 mm (22.5 g). 

Thioacetic333 and thiobenzoic acid 333,334 In a 1-1 flask fitted with a stirrer and reflux condenser, anhydrous pyridine (200 ml) is saturated by a stream of hydrogen sulfide that has been washed by iodine solution and dried through calcium chloride. It is then treated with acetyl chloride (40 g) with stirring and cooling to below 15° for 2-3 h alternatively, benzoyl chloride (40 g) is similarly added at 5°. Thereafter the mixture is acidified with the calculated amount of 5N-sulfuric acid and extracted with ether. The extract is dried over sodium sulfate and fractionated in a stream of nitrogen, giving thioacetic, b.p. 87.5-88°, or thiobenzoic acid, b.p. 85-87°/10 mm, in 60-65 % yield. 

---