Dimethyl Sulfoxide-Phosgene

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(DMSO) [67-68-5] C2H6OS (MW 78.13) InChI = 1S/C2H6OS/c1-4(2)3/h1-2H3 InChIKey = IAZDPXIOMUYVGZ-UHFFFAOYSA-N (COCl2) [75-44-5] CCl2O (MW 98.92) InChI = 1S/CCl2O/c2-1(3)4 InChIKey = YGYAWVDWMABLBF-UHFFFAOYSA-N (oxidant for the conversion of primary and secondary alcohols to aldehydes and ketones, respectively; avoids overoxidation to carboxylic acids; because of the high toxicity of phosgene and the absence of any clear advantages, the use of this procedure is not recommended) Physical Data: DMSO: mp 18.4 °C; bp 189 °C; d 1.101 g cm−3. COCl2: bp 8.2 °C/760 mmHg; d 1.432 g cm−3 (4 °C). Solubility: DMSO: sol H2O, alcohol, acetone, THF, CH2Cl2. COCl2: reacts slowly H2O; sol CH2Cl2, THF, benzene. Form Supplied in: DMSO is a colorless liquid; widely available, including ‘anhydrous’ grades of DMSO packed under N2; COCl2 is a gas available in cylinders. Preparative Method: the active reagent is proposed2 to be , formed from the reaction with DMSO of the chloroformate RR1CHO2CCl separately generated from phosgene and the alcohol. Purification: DMSO: distillation from calcium hydride at 56–57 °C/5 mmHg,3a or 83–85 °C/17 mmHg;3b storage over 3A molecular sieves. COCl2: distillation. Handling, Storage, and Precautions: Dimethyl Sulfoxide is readily absorbed through the skin and should always be handled with gloves in a fume hood; its reactions form foul-smelling byproducts and should be carried out with good ventilation, and the waste byproducts and liquids used for washing should be treated with KMnO4 solution to oxidize volatile sulfur compounds; DMSO undergoes appreciable disproportionation to dimethyl sulfide (stench) and dimethyl sulfone above 90 °C;3c Phosgene, also known as carbonic dichloride, is corrosive, moisture sensitive, and highly toxic, and should only be used with extreme caution.