DD139852B1 - PROCESS FOR PREPARING CRYSTALLINE-FLUID SUBSTITUTED 1,3-DIOXANES - Google Patents

Description

Process for the preparation of crystalline-liquid substituted 1,3-dioxanes

Field of application of the invention

The invention relates to a process for the preparation of crystalline-liquid substituted Ί, 3-dioxanes, which due to their favorable properties, e.g. can be used in optoelectronic components.

Characteristic of the known technical solutions

The substances produced by the process according to the invention are novel and processes for their synthesis have hitherto not been known.

Object of the invention

The 2iel of the invention consists in the production of crystalline liquid substituted 1,3-Dioxane.

Explanation of the essence of the invention

It has been found that crystalline liquid 2,5-disubstituted derivatives of 1,3-dioxane of the general formula

(Ι)

in which

or X = R ⁴ and Y = R ³

or X = R ¹ - ^) - and Y = R ³ - ^ 3) -, as well as

^r1 - ^C n ^H 2n-H ^J V

R ⁴ - <h) -C00; C _n H _{2n + 1} OCOO; C _n

) N; CN; N0 _£ ; F; Cl; Br; NC-CH = CH; NC-CH ₂ -CH ₂ ; NC-CH ₂ , R ² = C _n H _{2n + 1} ; OH; CN; OR ⁴ ; OCOR ⁴ ; OCOOR ⁴ ; OCO - <-> - R ¹ ;

OCO- (H) -R ⁴ ;

^r4 - ^C n ^H 2n ₊ i

with η * = 1 to 10,

can be prepared by reaction of alkanals, substituted benzaldehydes or their acetals with glycerol or 2-substituted Propandiolen- (i, 3) in organic solvents in the presence of an acidic catalyst according to the general scheme:

X - CHO + CH - Y ►X- / N-Y

and which may still be esterified or etherified

In the previously known 2-phenyldioxane derivatives (5-dioxane derivatives are hitherto unknown at all), the synthesis produces predominantly cis product jja.B · ice t trans is 9: 1 in Eliel et al *, J _# Chem «Soc · 98, 956 (1976) 1, in which no crystalline-liquid properties are to be expected. Surprisingly, it was found in the synthesis method according to the invention that, when the D-alkyl and n-alkylaryl substituents are used, predominantly (about 60-80 #) trans product is formed with crystalline liquid properties.

Dioxanes are relatively easy to hydrolyze as cyclic acetals. This initially produces the hemiacetal compound, which, as a noncyclic compound, permits a slight rearrangement from the trans to the cis form. Surprisingly, this effect does not occur when using our starting materials, i. The dioxane derivatives according to the invention are much more stable to hydrolysis than the EU would expect. The processes for the preparation of dioxane derivatives which are described in the literature always give mixtures of isomers with a predominant cis-Aoteil. The separation of the isomers is complicated and cumbersome (eg gas chromatography or column chromatography ) and gives low yields of the pure isomers · The compounds represented by us, predominantly trans product, are easily and in high yield to be liberated from the cis isomers by simple recrystallization. The occurrence of crystalline-liquid properties is by no means self-evident and only with dioxane derivatives to be expected if they are in the chair form with bis-equatorial substituents. The process according to the invention surprisingly favors this formation ·

Example 1:

Preparation of 2 ~ alkyl propandiole- (i, 3) (s. Tab. 1) and the 2- / ~ 4-substituted phenyl _{<_7-propandiole-} (i, 3) (s. Tab. 2).

In a 2 1 three-necked flask 21 g (0.5 mol) of LiAlH ₄ in 1 1 abs. Ether submitted. ^u nder ice cooling and vigorous stirring, 1 mole of n-Alkylmalonester or 1 mole of 4-substituted phenylmalonester, with the same volume of abs. Ether is mixed slowly added and then stirred for a further 2 hours at room temperature. Then the solution is carefully mixed with 100 ml of ice water. The resulting precipitate (Al (OH) ₃ , LiOH) is dissolved by adding 700 ml of 10% H ₂ SO ₄ . The organic phase is separated, the aqueous phase is etherified twice and the combined organic phases washed with 2 #iger NaHCO ₃ solution and water. After drying with Na, the solvent is distilled off in vacuo and the residue is fractionally distilled. Examples are given in Tab. 1 and 2.

Table 1

η yield

kgf / mm

3 63 92-93 / 2.5 4 69 107-110 / 2 5 65 125-126 / 2.5 6 73 133-136 / 2.5 7 75 F: 28-30 (petroleum ether) 8th 74 F: 44-46 (petroleum ether)

5 " ~ 4 -

table O Ti - ^ - CH (CB i ₂ öe P R yield 72-74 70-72 75 89 2: example

Preparation of compounds J ^, 2, 3,

Ю 0.1 mol of alkanal or 0.1 mol of substituted benzaldehyde or acetals thereof and 0.11 mol of 2-alkyl-propaudiol - (i, 3) or 0.12 mol of glycerol or 0.11 mol of 2 -, / f4-Subst.-phenyl_7-propanediol (i, 3) are dissolved in 150 ml of abs. Benzene, chloroform, methylene chloride, carbon tetrachloride or toluene in the presence of 100 mg of p-toluenesulfonic acid or AlCl ,, SbCl, TiCl ₄ or 2 ml of a mineral acid (HCl, H ₂ SO ₄ , H ₃ PO ₄ ) with stirring on a water until the Termination of the reaction heated. After cooling, the reaction mixture is washed with 2% NaHCO ₃ solution and water and dried over Na ₂ SO ₄ . The solvent is distilled off on a rotary evaporator and the residue is recrystallized from methanol. The yield is about 80 - 100% of theory. Examples are summarized in Tables 3, 4 and 5.

(о

- ft -

In the tables: K = crystalline solid, S., Sg = smectic A or B, N-nematic, I = isotropic-liquid,

Table 3

^x o- ^

Verb. R

1.1 HO C ₇ H ₁ 5 .107-1 09 _ _ - (. 41 - 1.2 C ₄ H ₉ C ₃ H ₇ • ^S B 26 C 40.5 - 25) 1.3 C ₃ H ₇ O C ₄ H ₉ , 43 - (. 38.5 40) * ^ ^ * C ₄ H ₉ O ^C 4 ^H 9 , 44 - C 44.5 C 35.5) 1 "5 C ₅ H ₁₁ O C ₄ H ₉ , 49 - C 43) 1o6 ^C 6 ^H 13 ° ^C 4 ^H 9 , 31 - C 41.5) C ₇ H ₁₅ O C ₄ H ₉ , 45 C 45) 1.8 C ₉ H ₁₉ O C ₄ H ₉ , 47 - 28.5). 35.5) 1.9 CN ^C 4 ^H 9 , 42 - - 40.5 1.10 C ₃ H ₇ O C ₅ H ₁ 1 , 37.5 · 29) 53 1.11 C ₄ H ₉ O C ₅ H ₁ 1 , 40 - 22) 50.5 1.12 C ₅ H ₁₁ O C ₅ H ₁ 1 , 38 ^ « Ю ♦ 56 1.13 ^C 6 ^H 11 ° C ₅ H ₁ 1 , 44 41). 55 C ₇ H ₁₅ O C ₅ H ₁ 1 , 45 C- C 56.5 UH C ₉ H ₁₉ O C ₅ H ₁ 1 , 48 48) 1.16 CN C ₅ H ₁ 1 , 55 - - uxl C ₃ H ₇ ^C 6 ^H 1 3 , 35 s _B 1.18 C ₄ H ₉ ^C 6 ^H 1 3 , 32 ³ B - 1.19 ^C 6 ^H 13 ^C 6 ^H 1 3 , 36.5 • 48) 1 ^ 20 C ₃ II ₇ O ^C 6 ^H 1 3 , 40

Continued table

Verb. R

1.21 1.22 1.23 1.24 1.25 1.26

C ^ H

6 ^H 13 • 35.5. 44

1.28

1.29

1 "30

1.31

1:32

1:33

1c34

1:35

1:36

1:37

^C 6 ^H 13 ° C ₇ H ₁₅ O

C ₉ H ₁₉ O

br

NO ₂

CN

C ₄ H ₉ O

^C 6 ^H 13 ° CN

^C 6 ^H 13 C ₂ H ₅ O

^C 4 ^H 9

C ₅ H ₁₁ O

Br CN

C ₆ H ₁₃ . C ₆ H ₁₃ .

^C 6 ^H 13 ^C 6 ^H 13 ^C 6 ^H 13 ^C 6 ^H 13 ^C 6 ^H 13

₇ H ₁₅

•. 46. 45. 50 "55.5

:. 39)

c _? H

C ₇ H ₁₅

C ₇ H ₁₅

C ₈ H ₁₇

C ₈ H ₁₇

C ₈ H ₁₇

^C 8 ^H 17 *

C ₈ H ₁₇

C ₈ H ₁₇

56 - 47 - 49 · 59.5 37.5. 62

54 - 38. 60

55 - 43. 62 38

48

 60

50 49 53 55 56.5

(40.5)

;. 52)

C 55)

table

-O'

Vexb.

· 2! C ₃ H ₇ C ₄ H ₉ O 2.2 C ₆ H ₁₃ C ₄ H ₉ O.

26 - -

, 50

Table 5

Verb. R ¹ R ³ KSS ^ N

^C 6 ^H 13 OC ₄ H ₉ O , 136 ( Л'с IA) . 166 - * "* · 3.2 CN C ₄ H ₉ O о 121 - - - - г 2Ѳ2. CN с 83 - - - - .152 · Example 3:

Process for the etherification of 2- / 4,4-hydroxy-phenyl-7-5-alkyl-1,3-dioxanes

1. 0.1 mole of 2 - ^ "" 4-hydroxy-phenyl _<i> y-5-alkyl-1,3-dioxane "dissolved in 50 ml of absolute tetrahydrofuran and 10 with 0.12 mol.

Natxiumhydrid added. Naoh. stirring is continued for 2 hours, 0.12 mole of corresponding alkyl bromide is added and the reaction mixture is refluxed for 4 hours. Thereafter, the solvent is distilled off on a rotary evaporator, the reaction product was taken up in 100 ml of ether and the ethereal phase washed twice with 100 ml of water. The mixture is then dried over Na ₂ SO ₄ , the solvent is distilled off and the residue is recrystallized from methanol (Table 6).

2. 0.1 mol of 2 ~ ^ 4-Hyaxoxy-phenyl_7-5-alkyl-1,3-dioxane ^{is dissolved} in a little benzene and added to a suspension of 0.23 g (0.1 g-atom) of sodium in 100 ml Section. Given toluene. After three hours of heating to 80 ⁰ C is cooled to room temperature and added 0.11 mol of alkyl bromide. The mixture is then heated to 80 ⁰ C for 4 hours and washed after cooling, the reaction mixture with water over Na _? S0> dried, the solvent was distilled off and the reaction product from methanol crystallized (Table 6).

0.1 mole of 2-ol ~ 4-hydroxy-oxy-phenyl_7-5-alkyl-1,3-dioxane are added with stirring to the bed of 0.23 g (0.1 g-atom) of sodium in 100 ml of abs. Ethanol registered. Thereafter, 0.1 mol of alkyl bromide are added and the mixture heated for 4 hours at reflux. After distilling off the solvent, the residue is taken up in ether, washed over Na "SO. dried, distilled off the ether and the reaction product from methanol recrystallized (Table 6).

Table 6

RO

m ^H 2m + 1

Verb. R

Yield n.Variant K

1.4 ^C 4 ^H 9 4 95 83 85 , 44 - - ( _к . 40). 1.13 ^C 6 ^H 13 5 93 - 71 , 44 (.22) , 56 1.24 с ₇ н _і5 6 96 75 78 , 45 .50,5 , 55 example 4:

A process for the esterification of 2 - / - 4-hydroxy-phenyl-7-5-subst.-1,3-dioxanes and 2 - / 4 -4 -sufon-phenyl-7-5-hydroxy-1,3-dioxanes

1. The sodium salt of 0.1 mol of 2- / ~ 4-hydroxy-phenyl _ / - 5-subst.-1,3-dioxanes (prepared according to Example 3) in abs. Tetrahydrofuran, ether, benzene or toluene with stirring with 0.15 mol of corresponding acid chloride. The batch is left to stand overnight, the solvent is distilled off, the residue taken up in ether, washed, dried with NapSO- and recrystallized from methanol. The yield is 90-95 of theory.

2. 0.1 mol of 2- / f * 4-hydroxy-phenyl_7-5-subst.-1,3-dioxane or, 0.1 mol of 2- ^ ~ 4-subs t-phenyl J7-5 --- Hydroxy-1,3-dioxanes are dissolved in 15 ml abs. Dissolved pyridine and slowly added with cooling and stirring 0.11 mol of corresponding acid chloride. The reaction mixture is allowed to stand overnight, the solvent is then distilled off and the residue is worked up as described under 1. above. The yield is 90 fo of theory.

Table 7

R-COO-

Verb. R

1:38 C ₄ H ₉ 1:39 C ₅ H ₁₁ 1:40 ^C 6 ^H 13 1:41 CH ₃ O- 15 1.42 C ₅ H ₁₁ 1:43 CF ₃ - < 1:44 NC <f

34

5 о 27 ³ A 30 5 , 42 C ₇ H ₁ 5 • 80th к _ - 5 , 148.5. C ₇ H ₁ 5 , 85 - - .193 C ₇ H ₁ 5 .1 03 - - , 174 C ₇ H ₁ 5 .1 13 ³ A 166th C ₇ H ₁ VJL .1 29 ³ A 182nd , 221

Table 8

R-

Verb. R

R-

1.45 1.46

NO,

C ₆ H ₁₃ O--

O ₂ NO

.143. 159

11 - Hl -

example

Synthesis protocol for 5-alkyl-2- / 4- (β-cyanoethyloxy) -phenyl-7,3,3-dioxanes and 5-β-β-cya xxy% hyloyLyJJ-Z- £ ~ A-sv.sup.- phenyl .JT-i, 3-dioxane

To a solution of 0.1 mol of 5-alkyl-2-4-hydroxyphenyl-7-1,3-dioxane or 0.1 mol of 2- / 4-substituted phenyl-7-5-hydroxy-1,3- dioxane is added to Ъеі 35 to 40 ⁰ C 300 mg of sodium methylate and 0.12 mol of acrylonitrile. The reaction batch is stirred for 6 hours at room temperature and then extracted with ether.

The ethereal phase is washed, dried with potash and the solvent distilled off. The residue is crystallized from methanol. The yield is 54-80 # of theory.

Claims (1)

He findsans pruch Process for the preparation of crystalline-liquid 2,5-disubstituted derivatives of 1,3-dioxane of general formula D- \ 'O ¹ (i) in which YR ² or X = R ⁴ and Y = R ³ - odex X * R ¹ - ^ - and Y * R ³ - <Q> - mean, as well ; R ^ - (Q) -COO; R ⁴ - (H>-C00; C _n H _{2n + 1} OCOO; C _q I ) N; CN; NO ₂ ; F; Cl; Br; NC-CH = CH; NC-CH ₂ -CH ₂ ; NC-CH ₂ R ₂ β ^c An + 1 ^{; 0H'CN ; 0r4} ' ^0C0r4 J OCOOR ⁴ ; -R ¹ ; OCO- (Н> -R ⁴ ; with η * 1 to 10,
characterized in that alkanals, substituted benzaldehydes or acetals are reacted with glycerol or 2-substituted propanediol (1.3) in orga African solvents in the presence of an acidic cata- gate, which are optionally esterified or etherified.