Kinetics and mechanism of hydrolysis of O-aryl N-phenylthiocarbamates

Phenyl Chloro(thionoformate): a New Dealkylating Agent of Tertiary Amines

“…analysis, the ammonium salt appeared to form instantly (d CH 2 4.35), and the chloroethane formation could be followed to completion over the next 30 min. As shown in Table 1, [10][11][12][13][14] the reaction of most unhindered tertiary amines also went to completion within 1 h. Olofson 7 has used N-ethylpiperidine as the benchmark for the determination of rate and selectivity of the dealkylation of tertiary amines by vinyl chloroformate, cyanogen bromide, phenyl chloroformate, ethyl chloroformate, 2,2,2-trichloroethyl chloroformate and benzyl chloroformate. The use of vinyl chloroformate gave the deethylated product in 90% yield but a period at 80° was required to effect decomposition of the intermediate salt.…”

“…7 We found that with 1 equiv. of (1), tropine was converted into a 2 : 1 mixture of tropine thiocarbonate (14) and the demethylated thiocarbamate (15). Efficient demethylation of tropine with (1) required prior acetylation of the hydroxy group.…”

“…102° (lit. 14 (ii) To a solution of N,N-dimethylaniline (0.2 g, 1.65 mmol) in dichloromethane (5 ml) was added phenyl chloro(thionoformate) (0.29 g, 0.23 ml, 1.65 mmol) followed by titanium tetrachloride (0.31 g, 0.18 ml, 1.65 mmol) and the solution refluxed for 16 h. The reaction mixture was washed twice with water (60 ml) and the solvent dried and evaporated affording a dark blue oil (0.362 g). The oil was purified by radial chromatography on silica (dichloromethane-light petroleum, 1 : 4) to give O-phenyl N-methyl-N-phenylthiocarbamate (12) as a pale yellow oil (0.04 g, 9%) with spectroscopic properties identical to those obtained above.…”

“…After 30 min a mixture (34 : 66) of compound (15) (spectroscopically identical with that above) and the carbothioate † (14) was obtained. For (14): 1 H n.m.r. …”

Synthesis of Phenyl Arylsulfonyl‐alkyl‐dithiocarbamates and Their Hydrolytic Reactivity in Hydroxide and Hydroperoxide Media

“…[6][7][8][9] We have previously studied the alkaline hydrolysis of aryl methyl-arylsulfonyl-carbamates [6] and have proposed a general base-catalysed mechanism for this reaction. This paper presents eight previously unreported phenyl arylsulfonyl-alkyl-dithiocarbamates 3 and proposes a mechanism for their hydrolytic decomposition in basic media.…”