4083-64-1

Moderately toxic by ingestion. Low toxicity by inhalation. A mild skin and moderate eye irritant.

clear liquid

p-Toluenesulfonyl isocyanate is a reagent used to prepare acetylated syn-1,2-diols,1 oxazolidin-2-ones,2 2,3-diamino acids,3 and N-tosylcarbonamides.4

Tetrahedron Letters, 35, p. 9609, 1994 DOI: 10.1016/0040-4039(94)88523-0

p‐Toluenesulfonyl Isocyanate (PTSI) is recommended especially for one‐component, low‐VOC polyurethane coatings. The reaction of PTSI with water introduced from pigments and solvents in the paint formulation generates carbon dioxide and soluble inert chemical products. Experience has demonstrated that 13 grams of PTSI effectively scavenges 1 gram of water. PTSI reacts with water in a 1 to 1 molar ratio, generating PTSA and carbon dioxide gas. This reaction occurs readily at room temperature and does not require heating. The PTSA generated in the process is essentially an inert material that does not further react with PTSI or other isocyanate groups, resulting in the formation of insoluble ureas. The hydroxyl group is reacted with excess p-toluenesulfonyl isocyanate (TSI) to form an acidic carbamate. Water is added to convert unreacted isocyanate to sulfonamide, followed by direct potentiometric titration of the acidic carbamate with tetrabutylammonium hydroxide (Bu4NOH) in nonaqueous medium.

Danger! Harmful if swallowed, inhaled or absorbed through the skin. Causes skin and severe eye irritation. It may cause an allergic respiratory response. Reacts spontaneously and violently with water, alcohols, amines, acids and alkaline solutions. These substances should not be poured into a vessel containing PTSI. Prolonged exposure of PTSI to elevated temperatures can result in violent decomposition. Temperatures above 170?C are to be avoided. Reaction with water results in the generation of carbon dioxide. Reaction vessels should be vented to avoid pressure build‐up. Vent through a calcium chloride tube to prevent moisture from entering vessels. Do not get in the eyes, on the skin, or clothing. Avoid breathing vapour or mist. Keep the container closed. Use with adequate ventilation. Wash thoroughly after handling. If handled indoors, provide adequate mechanical exhaust ventilation or wear NIOSH/MSHA approved air ‐line respirator or SCBA. Wear impervious PVC or rubber gloves, goggles, and protective clothing. PTSI must be stored in air‐tight containers.

Add the organic azide (0.75 mmol), Pd(OAc)2 (5.6 mg, 5 mol%) to an oven-dried Schlenk tube (10 mL). Purge the tube and backfill with CO (three cycles) from a balloon. Inject anhydrous MeCN (3.0 mL) into the tube. Stir at 80??C for 4 h under CO atmosphere (balloon). Concentrate the mixture under reduced pressure. Purify the residue by column chromatography (petroleum ether/EtOAc 3:1.-.1:1).