Juan C. Vega

Synthesis of Diacyl Sulfides by Phase Transfer Catalysis

Abstract The symmetrical monothioanhydrides or diacyl sulfides have been synthesized by several methods. They are formed by acylation of free monothioacids or their anions1, by acylation of potassium2 or lithium3 sulfide, from the reaction of monothiocarboxylic acids with dicyclohexylcarbodiimide4 or by treatment of trimethylsilyl thiocarboxylates with acyl chlorides4. The recent publication about diacyl disulfides synthesis using phase transfer catalysis5 promted us to communicate our own results applying this technique to the preparation of the closely related diacyl sulfides. These compounds may be obtained by a more simple procedure than the published methods and in very high yields by the reaction of acylchlorides (1) with sodium sulfide nonahydrate in a solid-liquid system consisting of dichloromethane, the mentioned salt and hexadecyltributylphosphonium bromide as a phase transfer catalyst.

REACTIONS OF DICHLOROMETHANE WITH THIOANIONS. 2. FORMATION OF 5-ALKYL-1,3,5-DITHIAZINANES, 3,5-DIALKYL-1,3,5-THIADIAZINANES, AND 1,3,5-TRIALKYL-1,3,5-TRIAZINANES BY REACTION OF DICHLOROMETHANE WITH SODIUM SULFIDE AND MONOALKYLAMINES

Abstract The reaction of dichloromethane with sodium sulfide and monoalkylamines, catalyzed by polyethyleneglycol 1,500, is studied. A mixture of 5-alkyl-1,3,5-dithiazinane, 3,5-dialkyl-1,3,5-thiadiazinane, and 1,3,5-trialkyl-1,3,5-triazinane is obtained. The proportion of these heterocycles depends on the amine structure and the presence of sodium hydroxide.

Reactions Of Dichloromethane with Thioanions. 1. Preparation Of Bis(N,N-Dialkylthiocarbamoylthio)Methanes

Abstract The preparation of some bis(N,N-dialkylthiocarbamoylthio)methanes, mainly published in the patent literature, is described. The method is based on the reaction of sodium N,N-dialkyldithiocarbamates in water with dichloromethane catalyzed by poly(ethylene glycol) 1,500. The yields are 50-80%.

PYROTHIOCARBONATES I. AMINOLYSIS OF S-(ETHOXYCARBONYL) O-ETHYL DITHIOCARBONATE

Abstract The reaction of S-(ethoxycarbonyl) O-ethyl dithiocarbonate (1) with equimolar amounts of butylamine, benzylamine, diethylamine and piperidine in ethanol solution at 0°C is reported. The mole ratio of O-ethyl thiocarbamate (2) and O-ethyl carbamate (3) formed as main products is larger than unity during all the reaction. Bis(ethoxythiocarbonyl) sulfide (4) and bis(ethoxycarbonyl) sulfide (5) are also produced and their formation is explained in terms of the reaction of 1 with EtOCS2 − and EtOCOS−, respectively, which are the leaving groups in the aminolysis of 1. Reactions 4 → 2 and 5 → 3 also take place. When 50% of 1 has been consumed compound 4 is not detected and compound 5 is found at very low concentration, indicating that generation of 4 and 5 occurs mainly after aminolysis of 1. The fact that the ratio of 2:3 is larger than unity in this aminolysis step, and that S-methyl O-ethyldithiocarbonate is aminolyzed more readily than S-methyl O-ethylmonothiocarbonate under the same conditions as t...

PYROTHIOCARBONATES V. SYNTHESIS AND SOME REACTIONS OF S-TRIMETHYLSILYL O-ALKYLDITHIOCARBONATES

Abstract Non-reported S-trimethylsilyl O-alkyldithiocarbonates (2) are prepared by reaction of O,O-dialkyltrithiodicarbonates with N-methyl N-trimethylsilylaniline in 87-96% yield. These are air-sensitive liquids which are separated from the accompanying phenyl methyl alkylcarbamothioates by fractional distillation. The reaction of 2 with acetyl chloride gives the unsymmetrical dithioanhydrides S-acetyl Oalkyldithiocarbonates in 93-97% yield. With the less powerful electrophilic reagent, iodomethane, Strimethylsilyl O-ethyldithiocarbonate (2a) forms S-methyl O-ethyldithiocarbonate in 30% yield. When a chloroform solution of 2a is stirred with water the unstable compound O-ethyldithiocarbonic acid is obtained.

REACTIONS OF DICHLOROMETHANE WITH THIOANIONS. 3. PREPARATION AND AMINOLYSIS OF BIS(ALKOXYTHIOCARBONYLTHIO)METHANES

Abstract Bis(alkoxythiocarbonylthio)methanes are prepared by reaction of sodium O-alkyldithiocarbonates in water with dichloromethane catalyzed by polyethylenglycol 1,500. The aminolysis of these products with monoalkylamines, in 1:7 molar proportion, in the presence of CH2Cl2 and the polymer above, affords 5-alkyl-1,3,5-dithiazinane, and dialkylcarbamothioate, in 1:2 molar proportion.

Synthesis of Potassium 4-(alkoxycarbonylthio)- and 4- (Aalkoxythiocarbonylthio)-3,5-Dinitrobenzenesulfonates as Amphiphiles

Abstract The titled compounds are prepared by reaction of potassium 4-chloro-3, 5-dinitrobenzenesul-fonate with potassium O-alkylthiocarbonates or O-alkyldithiocarbonates with yields higher than 70%.

Pyrothiocarbonates. Part 2. Reaction of S-ethoxycarbonyl O-ethyl dithiocarbonate with some potassium O-alkylthiocarbonates

The thiolysis of S-ethoxycarbonyl O-ethyl dithiocarbonate (1) has been examined in order to study both its transesterification reaction and the reactivities of its carbonyl and thiocarbonyl groups. The two symmetrical pyrothiocarbonates (EtOCS)2S (4) and (EtOCO)2S (5) are produced by reactions of (1) with EtOCS2K (7) or EtOCOSK (8) in 95% ethanol at 0 °C; (4) was always the main product in the reaction with (7) whereas (5) was initially the main product in the reaction with (8). The reaction of (1) with BuOCS2K yielded first BuOCS2CSOEt and then BuOCS2CO2Et and (BuOCS)2S. These results indicate that the thiocarbonyl group of (1) is more reactive than the carbonyl one.