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The published data on the methods for the preparation of mixed halogenobuta-1,3-dienes are generalised and systematised with a special emphasis on compounds of high practical value. Chemical transformations of mixed halogenodienes are considered and broad possibilities of the use of these compounds for the synthesis of various valuable, but difficultly accessible polyfunctional products are demonstrated. The bibliography includes 115 references.

Peroxyacetylenic menthol derivatives were synthesized by reaction of l-menthone with lithium 3-(tert-alkyldioxy)-3-methyl-1-butynides and were converted into the corresponding acetates by treatment with acetic anhydride. The thermal stability of the products was estimated by derivatography and quantum-chemical calculations.

The reactions of 4-ethoxy-2-(2,3,3-trichloro-1-nitro-2-propenylidene)benzazetine with methyl- and phenyllithium at a ratio of 1:2 result in replacement of one chlorine atom and formation, respectively, of 4-ethoxy-2-(2,3-dichloro-3-methyl-1-nitro-2-propenylidene)benzazetine and 4-ethoxy-2-(2,3-dichloro-1-nitro-3-phenyl-2-propenylidene)benzazetine in 45 and 52% yield. With excess phenyllithium (reactant ratio 1:5), a mixture of products is formed due to replacement of one, two, and three chlorine atoms by phenyl groups. An analogous reaction with methyllithium is nonselective.

X-ray structural data are used to demonstrate that the chlorine in the 5-position of the heterocycle is replaced on reaction of 3-trichloromethyl-4,5-dichloroisothiazole with sodium isopropoxide. The S-N and C-S bond lengths are lengthened in the resulting 3-trichloromethyl-4-chloro-5-isopropoxyisothiazole whereas the C-N and C-C bonds are shortened compared with analogous bonds in 4,5-dichloroisothiazole-3-carboxylic acid. This is explained by conjugation of the carboxylic acid with the heterocycle.

5-(2,5-Dimethylphenyl)-1,2-oxazole-3-carbaldehyde oxime reacted with acetic anhydride in pyridine to give 5-(2,5-dimethylphenyl)-1,2-oxazole-3-carbonitrile which was converted into the corresponding amide oxime by treatment with hydroxylamine. O-Acyl derivatives of N′-hydroxy-5-(2,5-dimethylphenyl)-1,2-oxazole-3-carboximidamide underwent heterocyclization into 5-substituted 3-[5-(2,5-dimethylphenyl)-1,2-oxazol-3-yl]-1,2,4-oxadiazoles on heating in acetic acid.

4,5-Dichloro-1,2-thiazol-3-amine was synthesized starting from accessible 4,5-dichloro-1,2-thiazole-3-carbonyl azide and -3-carboxamide via Curtius and Hofmann rearrangements, respectively. The procedure involving Curtius rearrangement was found to be more advantageous from the preparative viewpoint.

Reaction between 4-formyl-2-methoxyphenyl 4,5-dichloroisothiazole-3-carboxylate with various aromatic amines led to azomethins 2-7 formation. By treatment of azomethins 2-7 with sodium triacetoxyborohydride corresponding amines 8-11 were obtained. During the bioassays of new vanillin derivatives in mixtures with insecticides remarkable synergetic effect was discovered.

By treating with phosphorus pentoxide the 4,5-dichloroisothiazole-3-carboxamide 4,5-dichloro-3-cyanoisothiazole was synthesized whose reactions with piperidine, phenyl-and benzylthiols occurred with replacement of the chlorine atom in the position 5 by the residue of the corresponding nucleophile. Reactions with sodium thiobytylate and also with sodium methylate in methanol led to the formation both of the products of chlorine substitution by BuS or MeO groups respectively and of addition products of methanol to the cyano group. The reaction of butanethiol with cyanoisothiazole in 2-propanol in the presence of sodium 2-propylate was more selective and resulted in the replacement of the chlorine atom in the position 5 by the residue of the butanethiol.

Reactions of 2-bromo-1-phenyl- and 2-bromo-1-(4-methylphenyl)-3,4,4-trichlorobut-3-en-1-ones with morpholine and diethylamine are accompanied by prototropic allylic rearrangement, leading to 3-amino-1-aryl-2-bromo-4,4-dichlorobut-2-en-1-ones as mixtures of E and Z isomers. The title compounds react with hydrazine, hydroxylamine, and thiourea to give the corresponding 5-aroyl-4-methoxypyrazoles, 3-aryl-5-hydroxyiminomethyl-4-methoxyisoxazoles, and 2-amino-4-aryl-5-trichlorovinylthiazoles.

By acylation of benzene, toluene, and p-xylene with 4,5-dichloroisothiazole-3-carbonyl chloride the corresponding aryl 4,5-dichloroisothiazol-3-yl ketones were obtained. By reaction of 4,5-dichloroisothiasol-3-yl 4-methylphenyl ketone with piperidine, alkyl(aryl) thiolates, sodium alcoholates, and 2,4-dinitrophenylhydrazine were synthesized 4-methylphenyl 5-piperidyl-4-chloroisothiazol-3-yl ketone, 5-alkyl(aryl)sulfanyl-4-chloroisothiazol-3-yl 4-methylphenyl ketones, 5-alkoxy-4-chloroisothiazol-3-yl 4-methylphenyl ketones, and 2,4-dinitrophenylhydrazone of the initial ketone respectively.

Reaction of 1,1,4,4-tetrachloro-3-buten-2-one with 3,5-dimethylpyrazole gave 1,1-dichloro- 4,4-bis-(3,5-dimethyl-1-pyrazolyl)-3-buten-2-one. Treatment of the latter with amines resulted in replacement of one pyrazole ring by the amine residue with formation of the corresponding 4-amino-1,1-dichloro-4-(3,5- dimethyl-1-pyrazolyl)-3-buten-2-ones.

Previously unknown 4,5-dichloroisothiazole-3-carboxylic acid amides and esters were synthesized by reactions of 4,5-dichloroisothiazole-3-carbonyl chloride with ammonia, heterocyclic and aromatic amines, and functionally substituted alcohols and phenols.

Reactions of 1-adamantanecarbonyl chloride with functionally substituted alcohols, phenols, amines, thiols, and ketone oximes gave hitherto unknown 1-adamantanecarboxylic acid esters, amides, and thio esters, including those containing a peroxide group.

From 3,4,4-trichloro-3-butenoic acid 3,3,4,4,4-pentachlorobutanoic, 3,4,4,4-tetrachloro-2-butenoic, and 2,3,4,4-tetrachloro-3-butenoic acids were synthesized. By Friedel &-Krafts reaction from 3,4,4-trichloro-3-butenoyl and 3,3,4,4,4-pentachlorobutanoyl chlorides with aromatic hydrocarbons the corresponding aryl chloroalkyl ketones were prepared. It was established that dehydrochlorination of 2,2,3,3,3-pentachloropropyl phenyl ketone with aqueous alkali under conditions of the phase-transfer catalysis at the molar ratio of reagents ketone:KOH:triethylbenzylammonium chloride equal to 1:4:0.05 involved the cleavage of two HCl molecules and resulted in 3,3,3-trichloro-1-propynyl phenyl ketone.

A procedure has been proposed for the synthesis of tertiary acetylenic alcohols and diols by treatment of phenylacetylene or 2-methyl-3-butyn-2-ol with butyllithium and subsequent reaction of lithium phenylacetylide or lithium 4-lithio-2-methyl-3-butyn-2-olate thus obtained with alicyclic, aromatic, and terpene ketones.

Synthesis of tertiary acetylene alcohols was developed based on 1-octadecyne treatment with butyllithium followed by reaction of 1-octadecynyllithium with aliphatic, aromatic, alicyclic, and terpene ketones.

Reaction of 3,4,4-trichloro-1-(4-methylphenyl)-3-buten-1-one with amines results in replacement of the internal chlorine atom and is accompanied by prototropic allyl rearrangement leading to formation of the corresponding 3-amino-4,4-dichloro-1-(4-methylphenyl)-2-buten-1-ones. The reaction of the title compound with 2,4-dinitrophenylhydrazine yields 3,4,4-trichloro-1-(4-methylphenyl)-3-buten-1-one 2,4-dinitrophenylhydrazone and is not accompanied by allyl rearrangement.