ISOTHIAZOLES .5. CYCLOADDITION REACTION OF NITRILE OXIDES TO 3-DIETHYLAMINO-4-(4-METHOXYPHENYL)-ISOTHIAZOLE 1,1-DIOXIDE - AN ENTRY TO 5-ACYL- AND 5-CYANO-ISOTHIAZOLE 1,1-DIOXIDE DERIVATIVES

摘要

Nitrile oxides 2 reacted with 3-diethylamino-4-(4-methoxyphenyl)-isothiazole 1,1-dioxide (1) affording through a highly regioselective 1,3-dipolar cycloaddition reaction isothiazolo[5,4-d]isoxazoline 4,4-dioxides 3. Reduction of 3 afforded a mixture of the E and Z forms of the corresponding 5-(amino-arylmethylene)-dihydro-isothiazole 1,1-dioxides 4/5 which were transformed into 5-acyl-dihydro-isothiazole 1,1-dioxides 6 and the corresponding dehydrated products 7. Compound 3 f was easily transformed into 5-cyanoisothiazole 1,1-dioxide 11. [References: 17]