4-toluenesulfonyl isocyanate

In the example shown, a 2-carboxamido-l,3-diene was formed as the byproduct [56]. p-Toluenesulfonyl isocyanate can be also used [57]. 

Phenyl isocyanate, p-tolyl isocyanate, p-toluenesulfonyl isocyanate, and p-chlorophenyl isocyanate were purchased from Aldrich Chemical Company and were distilled under vacuum prior to use. 

The compound 250 was reacted with chlorosulfonyl isocyanate followed by ethanol or -toluenesulfonyl isocyanate to give, respectively, 251 in 33% yield and 252 in 59% yield (Equation 20) <1982AP545>. In the case of chlorosulfonyl isocyanate, the reaction competed with an electrophilic substitution at the 2-position, forming 253 in 31% yield. 

Reaction of 274 with 2-thiophenesulfonyl chloride gave 275 (86EUP 150974) and with p-toluenesulfonyl isocyanate gave the sulfonyl urea 276... 

Specialty Isocyanates. Specialty isocyanates are organic isocyanates having the isocyanate function attached to a carbonyl group or to elements other than carbon. /t-Toluenesulfonyl isocyanate is used as a drying agent for organic solvents. Arenesulfonyl diisocyanates, such as m-phenylenedisulfonyl diisocyanate, are used as monomers for base-soluble polymers. Arenesulfonyl monoisocyanates are used as intermediates for pharmaceuticals and herbicides. 

Heating of the cycloadducts derived from arenesulfonyl isocyanates with dialkyl-carbodiimides in refluxing o-dichlorobenzene gives rise to the formation of N-sulfonylcarbodiimides and the lower boiling alkyl isocyanate. For example, reaction of p-toluenesulfonyl isocyanate 13 with di-n-butylcarbodiimide affords N-p-toluenesulfonyl-N -n-butylcarbodiimide 14 in 42 % yield. Reactions with DCC and diisopropylcarbodiimide proceed similarly. 

Analogous reactions of acyclic vinyl epoxides 15 with 4-toluenesulfonyl isocyanate also proceed with complete retention of configuration55. Enantiomerically pure epoxides such as 15b and c are readily available and reductive removal of the 4-toluenesulfonyl substituent from 16 is easily achieved. The transformation of 15c to 2-oxazolidinone 16c was used as the key conversion in a short enantioselective synthesis of acosamine55. 

Preparation of Hydrogel Arylsulfonyl Carbamates. To a solution of hydrogel (1-4.0 g) in dry pyridine (20-40 mL) was added eitherp-toluenesulfonyl Isocyanate (pTSI), 3.0 g, or p-nitro-benzenesulfonyl Isocyanate (p-NBSI), 0.5-3.0 g and the mixture was heated at 70 under nitrogen for 4 hr. The adduct was isolated by precipitation in benzene or ethanol. Repreclpltatlon from acetone or DMF yielded the desired products, IR (film) 3170 cm (-NH), 1530 cm" (-NO2), 1340, 1180 cm" (-SOj). The precise degree of substitution was determined by non-aqueous titration (Table II). 

This [3 + 2] strategy can also be extended to include other heteroatom substrates. The (-iq -allyl)Fp (3) reacts smoothly with toluenesulfonyl isocyanate to afford butyrolactam (20) (equation 12). ... 

ASTM El 899, Standard Test Method for Hydroxyl Groups Using Reaction with p-Toluenesulfonyl Isocyanate (TSI) and potentiometric titration with Tetrabutylammonium Hydroxide, 2002. 

When 3,4,5,6-tetrahydro-l,3-thiazine-2-thione (171) is treated with 4-toluenesulfonyl isocyanate... 

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