Pseudosaccharin ethers

Generally, 3-alkoxy- and 3-aryloxybenz [rfjisothiazole-1,1 -dioxides, pseudosaccharin ethers, (3) are obtained by reacting 3-chlorobenz-[d]isothiazole-1,1-dioxide (6) with the corresponding aliphatic or aromatic alcohols.3,20,24, 25, 120,232,233... 

On melting the benzophenonoxime pseudosaccharin ether, (91) undergoes what appears to be a two-stage rearrangement to (94)259 with (92) and possibly (93) as intermediate and transition state,260 respectively. 

The acetophenonoxime pseudosaccharin ether affords 3-anilino-benz[d]isothiazole-1,1 -dioxide (80) and apparently ketene under comparable conditions.254, 259 A similar mechanism involving 95 may be operative in the formation of 5b from 19 and dialkylcarbamoyl... 

Other derivatives are used in special cases either because no other derivatives of the corresponding alcohol are described, or because the commonly used derivatives are not suitable. For example, for the identification of glycols and their monoalkyl ethers pseudosaccharin ethers are suitable, while tert. alcohols are easily converted to S-alkylthiuronium salts via the corresponding alkyl chlorides. 

For the identification of glycols, their monoalkyl ethers, and esters of glycolic acid, alkyl pseudosaccharin ethers are suitable, which can be prepared by reacting the hydroxy compound with pseudosaccharin chloride in chloroform in the presence of pyridine, or also without any solvent (30, 31). 

Pseudosaccharin chloride (Expt 6.42) reacts with alcohols to give ethers (O-alkyl derivatives of saccharin) ... 

Oximes react very smoothly with the chloro compound 6 to form crystalline (benz d] isothiazolyl - 3 - oximino) alkane -1,1- dioxides ( pseudosaccharin oxime ethers ) (89 R = alkyl, aryl, R = H, alkyl, aryl).20, 28, 43,254 Since 6 reacts preferably with the oxime, the reaction is carried out in the presence of water.43... 

The pseudosaccharin 2-, 3- and 4-pyridylmethyl ethers (299) undergo facile singlet excited state reaction in methanol. Homolysis of the O-CH2 bond and radical recoupling yield the corresponding N-(pyridylmethyl)saccharin derivatives and hydrogen abstraction from the solvent yields saccharin. The nucleophilic photosubstitution product, pseudosaccharin methyl ether, is also formed as a minor product. ... 

A soln. of tetradecylamine and pseudosaccharin ethyl ether in acetonitrile stored 30 hrs. at room temp. 3-tetradecylaminopseudosaccharin. Y ca. 100%. - The reaction can also he performed in a shorter time at higher temp. F. e., also from pseudosaccharin chloride, s. H. Hettler, Z. Anal. Chem. 220, 9 (1966). 

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