Dibutyltin oxide

Polyhydric alcohol mercaptoalkanoate esters are prepared by reaction of the appropriate alcohols and thioester using -toluenesulfonic acid catalyst under nitrogen and subsequent heating (16,17). Organotin mercapto esters are similarly produced by reaction of the esters with dibutyltin oxide (18). Pentaerythritol can be oxidized to 2,2-bis(hydroxymethyl)hydracryhc acid [2831-90-5] C H qO, ... 

Chemical Properties. Trimethylpentanediol, with a primary and a secondary hydroxyl group, enters into reactions characteristic of other glycols. It reacts readily with various carboxyUc acids and diacids to form esters, diesters, and polyesters (40). Some organometaUic catalysts have proven satisfactory for these reactions, the most versatile being dibutyltin oxide. Several weak bases such as triethanolamine, potassium acetate, lithium acetate, and borax are effective as stabilizers for the glycol during synthesis (41). 

Organotin compounds such as monobutyltin oxide, the main substance used, accounting for 70% of consumption, dibutyltin oxide, monooctyltin oxide, and dioctyltin oxide are used in certain esterification and transesterification reactions, at concentrations between 0.001% and 0.5% by weight. They are used in the production of substances such as phthalates, polyesters, alkyd resins, fatty acid esters, and adipates and in trans-esterifications. These substances are in turn used as plasticizers, synthetic lubricants, and coatings. Organo-tins are used as catalysts to reduce the formation of unwanted by-products and also provide the required colour properties (ETICA, 2002). 

Dibutyltin oxide 0% degradation In 28 days No biodegradation observed ... 

Hanstveit R (2003d) Dibutyloxostannane (Dibutyltin oxide, CAS 818-08-6) Determination of the ready biodegradability in a manometric respiration test. Delft, TNO, September (TNO Report No. V4016/01). 

CAS 818-08-6 Dibutyltin oxide RTECS WH7175000 Dibutyloxostannane UN 3146 Dibutyloxotin EC ANNEX 1 INDEX CgH gOSn / (C4Hg)2SnO EC/EINECS 212-449-1 Molecular mass 248.9 ... 

Reaction of the 2-alkenylnicotinonitrile 305 with trimethylsilyl azide and dibutyltin oxide under microwave irradiation gives a mixture of the tetrazolylpyridine 306 (52%) and the tricyclic tetrazolonaphthyridine 307 (22%). Compound 306 may be cyclized to 307 by treatment with />-toluenesulfonic acid (Equation 105) <2006T1849> and the reaction 305 —> 306 —> 307 may be made into a one-pot procedure, with an overall yield of 68%. 

Abbreviations PAH = polyaromatic hydrocarbon, TCDD = Tetrachlorodibenzo-p-dioxin, PCB = polychlorinated biphenyl, PBB = polybrominated biphenyl, TBTO = tributyltin oxide, DBTO = dibutyltin oxide, TPT = triphenyltin. 

Monoalkylation of a vic-glycol.1 Selective monoalkylation or monoacylation of the vic-glycol group of dimethyl L-tartrate is possible by conversion to the O-stannylene acetal (1) by reaction with dibutyltin oxide. The acetal is converted selectively to a mono derivative (3) by reaction with an alkyl halide or acyl chloride (excess) and CsF (about 2 equiv.). KF or Bu4NF are less effective than CsF. 

Reaction of glycosyl thioimidate 79 with aa -dibromo-m-xylene in the presence of NaH as a base and 15-crown-5 as a supporting reagent allowed the intermediate 80 (Scheme 4.88). Treatment of the diol 81 with dibutyltin oxide in dry toluene and then reaction with 80 in the presence of tetrabutylammonium iodide afforded the desired O-linked intermediate 82. Activation of this compound with NIS-TMSOTf afforded 83 in a good yield. Hydrogenolysis followed by acetylation gave the desired disac-... 

Anodic oxidation of a mixture of ds-cyclohexane-l,2-diol and cyclohexanol in methanol containing dibutyltin oxide and Et4NBr provides 2-hydroxycyclohexanone selectively, while cyclohexanol is recovered almost completely (Fig. 28) [146]. The cyclic intermediate dibutyl-(l,2-dioxycyclo-hexyl) stannan is oxidized indirectly by Br+. 

Bredenkamp, M. W. Spies, H. S. C. vanderMerwe, M. J., Structure elucidation of the dibutylchlorostarmyl intermediate during dibutyltin oxide-mediated acylation of sugars. Tetrahedron Lett 2000, 41, 547-550. 

Preparation of cyclodextrin derivatives substitution at a secondary hydroxyl group of the cyclodextrin annulus. Murakami and cowor-kers described a new and convenient method for the regioselective tosylation of the 2-hydroxyl groups of alpha, beta, and gamma cyclodextrin by means of a cyclic tin intermediate. The method is based on the reaction of dibutyltin oxide with 1,2-diols to form five-membered dibutyl-stannylidene derivatives. Useful yields of the 2-6>-tosyl derivatives of the cyclodextrins were obtained. 

Synthesis of PBHC. The procedure was the same as in the synthesis of PBH except 350g of BMA and 150g of HEA were used. After the copolymerization was finished, 147g of g, -caprolactone and 0.22g of dibutyltin oxide (DBTO) were added into the reaction product. The ring opening reaction of % -caprolactone in the presence of DBTO was carried out at 158-160 C for four hours, and then cooled to room temperature. 

Recently, the immobilization of dialkylmetal oxides, particularly dibutyltin oxide, on Amberlyst 45 ion-exchange resin, has been proposed for the esterification-transester-ification rcactionon model mixturcsatO.S °C,reaching92-100%conversioninll h [23]. 

Carbamates have been prepared by heating ethyl carbamate with a higherboiling alcohol in the presence or absence of catalysts [31-33], Aluminum iso-propoxide has been reported [34] to be an excellent catalyst for the interchange reaction between ethyl carbamate and benzyl alcohol. The interchange reaction is also effective for /V-alkyl carbamates as well as unsubstituted carbamates [35]. This catalyst is effective in preparing mono- and dicarbamates in excellent yields from primary and secondary alcohols and diols. Other effective catalysts are dibutyltin dilaurate [36], dibutyltin oxide [37], sulfuric acid or p-toluenesulfonic acid [31], and sodium metal (reacts with alcohols to give the alkoxide catalyst) [33]. 

The very inexpensive material sold undo- the name dibutyltin oxide is an amorphous, insoluble, polymeric powder with the composition BujSnO. A suspension of this powder in an appropriate organic solvent in the presence of a 1,2- or 1,3-diol becomes clear more or less quickly because of the formation of a stannylene. These derivatives are soluble in most solvents, polar or nonpolar. Equation (1) indicates the stoichiometry of the process ... 

A mixture of adenosine (267 mg, 1 mmol), dibutyltin oxide (250 mg, 1 mmol), and methanol (25 mL) was heated under reflux for 30 min and then evaporated to dryness. Two... 

A mixture of benzyl-fl-i>-galactopyranoside U (1 mmol) and dibutyltin oxide (1 mmol) in benzene was refluxed for 16 b, with azeotropic removal of water. The solution was evaporated to approximately 25 mL, tetrabutylammonium iodide (1 mmol) and benzyl bromide (0.25 mL) woe added, and the mixture was refluxed for 2 h. Evaporation to... 

A mixture of the diol (2 mmol) and dibutyltin oxide (545 mg 2.2 mmol) in benzene was refluxed overnight with azeotropic removal of water by a Dean-Stark condenser Evaporation of (he solvent at 100 0 then gave the crude stannylene derivative, which was used without further purification. Btominoiyses were carried out either on solutions of the stauaykne derivatives in benzene (5 mL) in the presence of 4-A molecular sieves (2 g)... 

The diol (1 mmol) was refluxed with dibutyltin oxide (1 Eq) for 12 h in toluene (20 mL) in an apparatus for the continuous removal of water. The toluene was removed on a vacuum line at 20°C, and the residue was dried for 30 min under reduced pressure (0.1 ton). The residue was taken up in dry chloroform (10 mL), and N-bromosuccinimide (NBS 1 Eq) was added. The stirred reaction mixture was monitorec by TLC. The reaction was complete at times ranging from 2 to 30 min. The mixture was poured directly onto a column for separation using die eluant listed for each compound. 

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