Boguslavskaya, L. S.; Chuvatkin, N. N.; Panteleeva, I. Yu., Journal of Organic Chemistry USSR (English Translation), 1982, vol. 18, # 10, p. 1832 - 1842
Vicarious nucleophilic substitution of hydrogen versus vinylic substitution of halogen in the reactions of carbanions of halomethyl aryl sulfones with dialkyl halofumarates and halomaleates
halomethyl aryl sulfone carbanions with dialkyl halofumarates and halomaleates results in nucleophilicsubstitution of hydrogen and/or of the halogen. The reaction with halofumarates proceeds via addition of the carbanions to the vinylic carbon atom connected with hydrogen, followed by base promoted β-elimination of hydrogen halide in which the halogen originates from the carbanion moiety or from the alkene
A process for producing a dicarboxylic acid compound represented by the formula (4):
wherein R
1
and R
2
are the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or a mixture of them, characterized by reacting a compound represented by the formula (2):
wherein R
1
, R
2
and the wavy line have the same meanings as the above, and one of X
2
and X
3
represents hydrogen and the other represents halogen, with nitrophenol represented by the formula (3):
in the presence of a base; a process for producing a nitrochromone compound represented by the formula (5):
wherein R
1
has the same meaning as the above, characterized by reacting the dicarboxylic acid compound or carboxylic acid thereof with an acid; a process for producing an aminochromone compound which comprises reducing the nitrochromone compound; and a process for producing an amidochromone compound which comprises acylating the aminochromone compound are provided.
A process for producing a dicarboxylic acid compound represented by the formula (4):
wherein R1 and R2 are the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or a mixture of them, characterized by reacting a compound represented by the formula (2):
wherein R1, R2 and the wavy line have the same meanings as the above, and one of X2 and X3 represents hydrogen and the other represents halogen, with nitrophenol represented by the formula (3):
in the presence of a base; a process for producing a nitrochromone compound represented by the formula (5):
wherein R1 has the same meaning as the above, characterized by reacting the dicarboxylic acid compound or carboxylic acid thereof with an acid; a process for producing an aminochromone compound which comprises reducing the nitrochromone compound; and a process for producing an amidochromone compound which comprises acylating the aminochromone compound are provided.
A process for producing a dihalosuccinic acid compound in which the proportion of a threo-dihalosuccinic acid compound is 70% or higher, which comprises adding a maleic acid compound to a halogenating agent.