Synthesis of 2-methyl-3,5,6-trichloro-4-pyridyl vinyl sulfone and its reactions with nucleophilic reagents

The reaction of excess primary aliphatic amines and mercaptans with 2-methyl-3,5,6-trichloro-4-pyridyl vinyl sulfone gives products of addition to the double bond.     

Reaction of pentachloropyridine N-oxide with potassium hydrogen sulfide

Depending on the conditions, the reaction of pentachloropyridine N-oxide with potassium hydrogen sulfide leads to the N-oxide of the potassium salt of 3,4,5,6-tetrachloropyridin-2-thiol or the dipotassium salt of 3,4,5-trichloropyridine-2,6-dithiol, which are converted by the action of dimethyl sulfate into the corresponding methylthio derivatives. Oxidation of the latter has given sulfones. It has been shown that for these sulfones,reactions with nucleophilic reagents take place at the methylsulfonyl group and not at the chlorine atoms.     

Synthesis and properties of 4-mercapto-2,3,5,6-tetrabromopyridine

2,3,5,6-Tetrabromopyridines with 4-mercapto, 4-chlorosulfenyl, and 4-chlorosulfonyl groupings were synthesized, and some of their reactions were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1514–1518, November, 1978.     

Pentabromopyridine

Methods for the preparation, of 3,5-dibromo- and 2,3,5,6-tetrabromo-4-hydroxypyridines and pentabromopyridine were modified. The structure of 2,3,5,6-tetrabromo-4-hydroxypyridine, which exists in the enol form, was established by means of its IR and PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 70–71, January, 1978.     

The reaction of pentachloropyridine with aliphatic amines

The reaction of pentachloropyridine with aliphatic amines has given a series of 2-alkylaminotetrachloropyr idines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7,pp. 959–962, July, 1970.     

Reaction of pent achloropyridine with sodioacetoacetic ester

Ethyl tetrachloro-4-pyridylacetoacetates and tetrachloro-2-pyridylacetoacetates were synthesized by reaction of pentachloropyridine with sodioacetoacetic ester. Hydrolysis of ethyl tetrachloro-2-pyridylacetoacetate gives 3,4,5,6-tetrachloro-2-pyridylacetic acid rather than the corresponding acetone derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 950–953, July, 1978.     

Rearrangement of 2,3,5,6-tetrachloro-4-pyridyl β-hydroxyethyl sulfone

A method for the preparation of 4-mercapto-2,3,5,6-tetrachloropyridine was modified. 2,3,5,6-Tetrachloro-4-pyridyl -hydroxyethyl sulfone was synthesized and converted to 4-hydroxytetra-chloropyridine by the action of a base. A mechanism for this rearrangement is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1642–1645, December, 1978.     

Reactions of 4-methyl(chloro)sulfonyl-2,3,5,6-tetrabromopyridines with nucleophilic reagents

The MeSO₂ group is replaced in the reaction of 4-methylsulfonyltetrabromopyridine with small nucleophiles, whereas the Br atom in the 2 position is replaced in the reaction with bulky nucleophiles. Depending on the temperature conditions and the ratio of the reacting substances, 4-chlorosulfonyltetrabromopyridine reacts with primary amines to give either the corresponding amides or amines. It was established that the corresponding amines are formed when tetrabromopyridinesulfonic acid -hydroxyalkylamides are heated with triethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 937–942, July, 1979.     

2, 3, 5, 6-Tetrachlorpyridine-4-sulfenyl chloride

2,3,5,6-Tetrachloropyridine-4-sulfenyl chloride has been prepared, and its reactions with nucleophilic reagents have been examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp 1232–1235, September, 1970.