99315-71-6Relevant articles and documents
Nitrile Sulphides. Part 3. Thermal Fragmentation of 1,3,4-Oxathiazoles: Formation of Nitrile Sulphides in a Retro-1,3-dipolar Cycloaddition Reaction
Paton, R. Michael,Robertson, Fiona M.,Ross, John F.,Crosby, John
, p. 1517 - 1522 (2007/10/02)
On thermolysis at ca. 160 gradC 1,3,4-oxathiazoles undergo retro-1,3-dipolar cycloaddition forming nitrile sulphides and carbonyl-containing fragments.The nitrile sulphides either decompose to sulphur and nitriles or are trapped as their 1,3-dipolar cycloadducts in the presence of dipolarophiles (dimethyl acetylenedicarboxylate, ethyl cyanoformate, benzonitrile, ethyl propiolate).Similar ratios (1.32, l.34, 1.33, 1.31) of 4- and 5-ethoxycarbonyl-3-(p-methoxyphenyl)isothiazole obtained from four sources of p-methoxybenzonitrile sulphide with ethyl propriolate provide strong evidence for product formation from a discrete intermediate nitrile sulphide rather than via direct interaction of precursor with dipolarophile. 2-Dichloromethylene-1,3,4-oxathiazoles, prepared by dehydrochlorination of 2-trichloromethyloxathiazoles, prepared by dehydrochlorination of 2-trichlorometyloxathiazoles, likewise fragment to nitrile sulphides, but attempts to trap dichloroketene were unsuccessful.
