Acetylation of hydrogen sulfide

Acetylanthracene, 30,1 Acetylation, of 2- -acetylphenylhydro-quinone, 34, 1 of hydrogen sulfide, 31, 105 a-Acetyl-7-butyrolactone, 31, 74 Acetyl chloride, 30, 1 (X-ACETYL-5-CHLORO-7-VALEROLACTONE, 31, 1... 

Figure 14.5 Relative initial rates of reduction [relative to nit-To-benzene (NB)] of 2-methyl-(2-CHj-NB), 4-chloro-(4-Ct-NB), and 4-acetyl- (4-Ac-NB) nitrobenzene (a) by dissolved natural organic matter constituents (DOM) in aqueous solution in the presence of hydrogen sulfide as bulk electron donor (Dunnivant et al.,...

When cucurbit cells are fed O-acetylserine or its metabolic precursors the rate of hydrogen sulfide emission in response to sulfate declines, and the incorporation of labeled sulfur from 35S-sulfate into cysteine increases (18). Inhibition of the synthesis of the O-acetylserine precursor acetyl coenzyme A by 3-fluoropyruvate (22) enhances hydrogen sulfide emission, but inhibits cysteine synthesis (1 ). These observations indicate that the availability of O-acetylserine is the rate limiting factor in cysteine synthesis. Hydrogen sulfide may be emitted to the extent the amount of sulfate reduced exceeds the synthesis of O-acetylserine. Therefore, direct release of sulfide from carrier-bound sulfide appears to be responsible for the emission of hydrogen sulfide in response to sulfate (Figure 1, pathway 1). 

Thiolacetic acid has been prepared from acetic acid and phosphorus pentasulfide 5 from acetyl chloride and potassium hydrosulfide 7 by the hydrolysis of diacetyl sulfide 8 from acetic anhydride and hydrogen sulfide 3-49 and from acetyl chloride and hydrogen sulfide in the presence of aluminum chloride.10 The procedure described 9 differs from other procedures employing acetic anhydride and hydrogen sulfide 3-4 most importantly in the use of alkaline rather than acidic catalysts, which the submitter found to cause slower absorption of hydrogen sulfide under pressure and to yield considerable diacetyl sulfide in addition to thiolacetic acid. 

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. 

Ceftiofur (57) differs from the preceding cephalosporin derivatives in that it ha.s a thioester moiety at C-3. This can be introduced by displacement of the C-3 acetyl group of 7-aminocepha-losporanic acid (40) with hydrogen sulfide and esterification with 2-furylcarboxylic acid to give synthon 5reacted with trimethylsilylated oximinoether derivative 55 (itself obtained from the corresponding acid by reaction with dicyclohexylcarbodiimide and 1-hydroxy-benzotriazole) to produce, after deprotecting, ceftiofur (57) [18]. 

The reaction of propylene sulfide or 3-chlon>propyl Qe sulfide with acetyl halides or hydrogen halides leads to good yields of the 2-halo-alhyl compound (LXXH) which results from cleavage of the seconds) y... 

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