CS270225B2 - Method of tetrahydropyran or furane derivatives production - Google Patents

Abstract

Compsn. comprises a heterocyclic cpd. of formula (I) in association with a suitable diluent or carrier. In (I), n is 1-3; X is O or S; each Rx is independently H or opt. halogenated 1-6C alkyl; R1 and R2 are each independently H, halogen or opt. halogenated 1-3C alkyl; Y is halogen; an opt. substd. phosphonium, sulphonium or ammonium cation with an associated anion; or a gp. -XR in which R is opt. halogenated 1-6C alkyl, -C(X)R1, SO2R1 or -N=C(R3R4) in which R1 is 1-6C alkyl, phenyl opt. substd. by alkyl and/or halogen, XR3 or NR3R4; R3 and R4 are each independently H or opt. substd. 1-4C alkyl.

Description

Ее invention relates to heterocyclic derivatives, or specific derivatives tetrahydropyran - furan useful as nematocides and insecticides · 270216 _л

Nematocidal and insecticidal compositions containing at least one heterocyclic compound of the general formula I as active substance are described in our related Czechoslovak patent specification δ · »oo ······

where n is an integer of 1 or 2,

X represents an oxygen atom or a sulfur atom, the substituents R _x , which may be the same or different, are selected from the group consisting of a hydrogen atom and optionally halogenated alkyl radicals of 1 to 3 carbon atoms, and R ₂ , which may be the same or different, in each case a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and

Y represents a halogen atom, or OSOgRf wherein R 'represents an alkyl group having 1 to 6 carbon atoms or a phenyl group optionally substituted with 1 to 3 alkyl groups having 1 to 4 carbon atoms or 1 to 3 halogen atoms, or if the compound it contains an asymmetric carbon atom, one of its enantiomers or, if the compound contains more than one asymmetric carbon atom, one of its diastereomers or one of its corresponding enantometers

Furthermore, the aforementioned patent epie describes a process for the production of a certain class of these active substances.

The present invention also relates to a further process for the production of a group of the above-mentioned active substances.

Accordingly, the present invention provides a process for the preparation of the active compounds of the formula II

(П)

wherein n is an Ciała of value 1 or 2, subetituenty R _x, which may be the same or different, are selected from the group consisting of hydrogen and an optionally halogenated alkyl radicals having 1 to 3 carbon atoms, ^R 1 ^{0 R} 2 * which can be the same or different, in each case represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and

Y represents a halogen atom or, if these compounds contain an asymmetric carbon atom, their enantiomers, or if these compounds contain more than one asymmetric carbon atom, their diaethereomers or the corresponding enantiomers,

CS 270 225 B2 which consists in the cyclisation of an alcohol of the formula III

wherein n, R _x , R j and R g are as defined above and in the isolation of the resulting product in the form of an individual enantiomer, diastereomer or a mixture thereof »

This cyclization is carried out by methods known per se in the presence of a halogenating and esterifying agent, for example using N-bronsuccinimide or tert-butyl hypobronite (see, in particular, M. Mlhailovic et al., Bull Soc. Chim Beograd, 1982, 47). (8), 407-415], or using a reagent consisting of a combination of lead acetate and a compound of formula M-hal, where M is an alkali metal or alkaline earth metal atom, especially lithium, sodium or israel and hal is halogen; S · Motohashi et al., Heterocycles, 1985, 23 »(8), 2035-2039] ·

Those compounds containing one asymmetric carbon atom exist in two enantiomeric forms R and S. In this case, the above formula II should be regarded as also defining a mixture of the two, either in equivalent proportions (racemate) or in such a ratio that either of these enantiomers is predominant ·

Compounds containing more than one asymmetric carbon atom exist in diastereomeric forms, and each diastereomer generally exists in two enantiomeric forms. ratio or in such a ratio where one of the components prevails ·

Preferred are those compounds of formula (II) in which n is an entire face of 1 or 2,

R _x, R and R ₂ are hydrogen, methyl or halomethyl groups, and

Y represents a halogen atom ·

Methods for the processing of the above active compounds into an overcoated nematocidal with an inecticidal agent, as well as tests for the efficacy of these compounds are disclosed in our above-cited Czechoslovak patent specification.

The invention is illustrated by the following non-limiting examples.

The structures of the resulting products were confirmed by NMR and / or iG spectrography and / or mass epectrography and / or microanalysis.

Example 1

Preparation of 6,6-dimethyl-2- (iodomethyl) tetrahydropyran (Compound 1)

A solution of 7.2 g of 2-methyl-6-hepten-2-ol in 100 ml of 1,2-dimethoxyethane is added to a solution of 44.3 g of lead acetate in 200 ml of 1,2-dimethoxyethane with stirring at 0 ° C, then a solution of 15 g of sodium iodide in 200 ml of 1,2-dimethoxyethane is added and stirring is continued for 30 minutes at 0 ° C. The reaction mixture is poured into a mixture of 1500 ml of ice-water and 500 ml of 10% hydrochloric acid and aqueous The ether phase is washed successively with saturated bicarbonate solution 270 225 B2

Sodium acetate, 10% sodium thiosulphate solution and saturated sodium chloride solution, dried over sodium sulfate and evaporated to dryness. The yellow residue is distilled under a vacuum of 2.7 Pa. 4 g of a yellow liquid product are obtained with a boiling point of 34 ° C. 2.7 Pa and the refractive index ngO _w formed by 6,6-dimethyl-2- (iodomethyl) -tetrahydropyrene of the formula

Example 2

Preparation of 2- (¢ 6, -dimethyl-dC-bromoethyl) tetrahydropyran (compound 2) and 5,5-dimethyl-2- (bromomethyl) tetrahydropyran (compound 3)

12.8 g of 6-methyl-5-hepten-1-ol and 19 g of N-bromo-succinimide are introduced into 75 ml of carbon tetrachloride and the mixture is stirred at room temperature for 8 hours. The reaction mixture is filtered, washed with 10% sodium thiosulfate solution and water, dried over sodium sulphate and evaporated to dryness. The residue is chromatographed on a silica gel column using a mixture of heptane and ethyl acetate (98 t 2) as eluent. 1.5 g of a colorless liquid consisting of 2- (δ, cG) are obtained. -dimethyl-bromomethyl) tetrahydropyrene (compound 2) of the formula

13g-NMR (62.90 MHz, deuterochloroform, O values in ppm vs. tetramethylsilane):

85.0, 69.0, 68.0, 30.7,

31.1, 26.9, 25.8, 23.5 ·

Using the same procedure, 8.0 g of 5,5-dimethyl-2- (bromomethyl) totrahydropyrene are obtained using 14.2 g of 2,2-dimethyl-5-hexen-1-ol and 21 g of N-bromosuccinimide in 150 g of carbon tetrachloride. (Compound 3), bp 48 ° C / 6.7 Pa, corresponding to the formula

Example 3

Preparation of two diastereomers of 2-bromobutyl-6-methyl-tetrahydropyran (compound a 5)

The reaction is carried out in an analogous manner to that of Example 2 except that n is used

6-methyl-5-hepten-1-ol uses 6-hepton-2-ol · After chromatography and the following products are obtained:

g of a colorless liquid formed by diastereomer A and g of a colorless liquid formed by diaethereomer В

CS 270 225 B2

2-bromomethyl-6-methyltetrahydropyran of formula

¹³ C-NMR ^{(62 MHz} · ⁹⁰ »CDCl in ppm versus tetramathylsilanu) Isomers Al 77.1, 74.6, 35.6, 33.0, 29.5, 23.5, 21.6; .

isomer B; 70.6, 67.9, 34.2, 31.1, 28.0, 19.4, 18.1.

The following compounds of formula II can also be prepared in an analogous manner to the preceding examples:

2-bromomethyltetrahydropyran (compound 6) of formula

C.

having a temperature of 74 ° C / 2.4 kPa;

2- (bromomethyl) tetrahydrofuran (compound 7), b.p. 70 ° C / 2.4 kPa, corresponding to the formula

C.

cis-bis (2,6-bromomethyl) tetrahydropyran (compound 8), m.p. 37 DEG C., corresponding to the formula

2- (1-bromoethyl) tetrahydropyran (compound

in the form of a mixture of two diastereomers in a ratio of ny with a refractive index of ngO 1.4855;

2- (chloromethyl) tetrahydropyran (compound: 45. The product results in the form of a liquid 10) of the formula

CS 270 225 B2

boiling point 55 ° C / 2 kPa;

2- (iodomethyl) tetrehydropyran (compound 11) of the formula

Boiling point 88 ° C / 1.6 kPaj

2- (fluoromethyl) tetrahydropyran (compound 12) of the formula

boiling at atmospheric pressure at 110 ° C ·

Claims (1)

A process for the preparation of tetrahydropyran or -furan derivatives of the general formula II (II) wherein n is a whole cell of 1 or 2, the substituents R _x , which may be identical or different, are selected from hydrogen and optionally halogenated alkyl radicals and 1 to 3 carbon atoms, R 6 and R 8, which may be the same or different, each represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and Y represents a halogen atom or, if these compounds contain an asymmetric carbon atom, their enantiomers or, if these compounds contain more than one aymmetric carbon atom, their diastereomers or the corresponding enantiomers, characterized in that the alcohol is of formula III ^In which n _t R p R ₂ and R _x are as defined above, cyclizes in the presence of a halogenation-etherification agent selected from the group consisting of brominated derivatives, such as N-bromo-succinimide or tert-butyl hypobromite, and lead acetate complexes; a compound of formula M-hal, wherein M is an alkali or alkaline earth metal atom and hal is a halogen atom, and the resulting product is isolated as an individual enantiomer, diastereomer or a mixture thereof. using the corresponding starting materials to give the compounds of formula (II) in which n, R p R ₂ and Y are as defined in point 1 and the substituents R _x , which may be the same or different, are selected from hydrogen and (C 1 -C 3) -alkyl radicals or, if these compounds contain an asymmetric carbon atom, their enantiomers, or they contain more than one asymmetric carbon atom, their diastereomers or their corresponding enantiomers ·