SU574432A1 - Method of obtaining acetal-orthoesters - Google Patents

Description

The use of basic catalysts such as diethylaniline pyridine, alkali metal acetates, increases the yield of the target product. The use of stronger bases - carbonates of alkali metals, triethylamine and others, is impractical due to the rapid polymerization of chloral. The process is conducted at an equimolar ratio of the reactants or with a slight excess of the orthoester.

Example 1. Preparation of dimethyl- (α-methoxy-p, p, p-trichloro) ethyl chloroformate.

To a suspension of 0.2 g of anhydrous sodium acetate in 4.5 g (0.042 mol) of methyl orthoformate, 7.0 g (0.042 mol) of chloral are added with stirring, heated at 90 ° C for 6 h and left overnight. The catalyst is filtered off and the filtrate is distilled. Obtain 5.3 g (50%) of the target substance with m. Kip. 118-120 ° C / 9 mm Hg. Art., 1.4570.

Found,%: C 28.46; P 4.38; C1 41.60

SbNp04S1z

Calculated,%: C, 28.43; P 4.37; C1 41.06.

Example 2. Obtaining diethyl- (a-ethoxy | 3, p, p-trichloro) -titlortraformate.

A mixture of 12 g (0.081 mol) of ethyl orthoformate, 10 g (0.068 mol) of chloral and 3 drops of pyridine was heated at 100 ° C for 6 h and distilled. Obtain 14.0 g (70%) of the target substance with m. Kip. 128-130 ° C / 7 mm Hg Art., p 1,4495.

Found,%: C, 36.70; H 5.76; С1 36.00 Г Ч О С

Incl.%: C 36.58; H 5.76; C1 36.05.

Example 3. Obtaining triethyl- (a-ethoxyr, P, p-trichloro) -ethyl chlorocarbonate.

A mixture of 10 g (0.048 mol) of ethyl carbonate, 7 g (0.048 mol) of chloral and 0.2 g of anhydrous sodium acetate is heated at 100 ° C for 6 hours. 8.4 g (58%) of the desired substance are obtained with a boil. 130-133 ° C / 7 mmHg, 1.4397.

Found,%: C 38.85; H 6.57; C1 31.10

CllH2lO5Cl3

Calculated,%: C 38.90; H 6.23; C1 31.00.

Example 4. Obtaining diethyl- (a-ethoxyr, p, p-trichloro) ethyl chloroformate.

0.2 g of anhydrous CHsCOONa in benzene is added to a solution of 12 g (0.081 mol) of ethyl orthoformate and 10 g (0.68 mol) of chloral and heated at 100 ° C under reflux for 6 hours. The catalyst is filtered off, the benzene is distilled off, the residue is distilled yut. Obtain 13.5 g (60%) of the target substance with m. Kip. 128-130 ° C / 7 mm Hg Art., 1,4495.

Found,%: C 36.58; H 5.71; C1 35.95

C9Hi7O4Cl3

Calculated,%: C, 36.58; H 5.76; C1 36.05.

Example 5. Obtaining diethyl- (a-ethoxyr, p, p-trichloro) ethyl chloroformate.

A mixture of 12 g (0.081 mol) of ethyl orthoformate and 10 g (0.068 mol) of chloral is left for two days at room temperature, heated for 6 hours at 100 ° C and distilled. Obtain 8 g (40%) of the target substance with m. Kip. 128-130 ° C / 7 mm Hg Art., p 1,4496.

 Example 6. Obtaining diethyl- (a-ethoxyr, p, p-trichloro) -ethyl orthoformate. A mixture of 12 g (0.081 mol) of ethyl orthoformate, 10 g (0.068 mol) of chloral and 5 drops of diethylaniline is heated at 100 ° C for 6 h and distilled. Obtain 13.8 g (68%) of the target substance with m. Kip. 128-130 ° C / 7 mm Hg Art.,

1.4495.

Example 7. Analogously to example 6, from 12g of ethyl orthoformate, 10 g of chloral and 5 drops of N-methylaniline, 13.8 g (68%) of diethyl- (a-ethoxy - P, | 3, p - trichloro)-ethyl chloroformate, t. Bale are obtained . 128-130 ° C / 7 mm Hg Art.,

1.4495.

PRI me R 8. Similarly to Example 6, 12.5 g of ethyl orthoformate, 10 g of chloral and 5 drops of dimethylaniline give 13.5 g (66%) of diethyl (a-ethoxy - p, p, p - trichlor) - ethyl orthoformate, m.p. 128-130 ° C / 7 mm Hg Art.,

“20 1,4495.

Example 9. Obtaining dimethyl- (a-methoxy-p p p-trichloro) -ethyl orthoformate.

A suspension consisting of 4.5 g (0.042 mol) of methyl orthoformate, 7.0 g (0.042 mol) of chloral, and 0.2 g of anhydrous CdCOOK is heated at 90 ° C for 6 hours and left overnight. The analyzer is filtered, the filtrate is distilled. Obtain 5.3 g (50%) of the target substance with m. Kip. 118-120 ° C / 9 mm Hg. Art.,

 1.4570.

Example 10. Analogously to example 9, but by carrying out the reaction in 12 ml of o-xylene, 5.0 g (49%) of dimethyl- (α-methoxyr, P, p-trichloro) -ethyl chloroformate, t. Kip.

118-120 ° C / 9 mm Hg. Art., 1.4570.

Example 11. Analogously to example 9, but when carrying out the reaction in 12 ml of dioxane receive 5.0 g (49%) of dimethyl- (a-methoxyP, P, p-trichloro) -ethyl chloroformate, t. Kip.

118-120 ° C / 9 mm Hg. Art., "2 ° 1.4570.

Claims (4)

Invention Formula I. The method of producing acetal-orthoesters of the general formula HE. CC-KN ORi ok ok W where RI, Kr, Ra is alkyl with 1-3 carbon atoms; R4 is hydrogen or alkoxy of 1 to 3 carbon atoms, characterized in that the chloral is treated with an aliphatic ortho ester of the general formula /HE : .. С-ОКg (s) ОЕз where RI, R2, Rs and R4 have the indicated values, at 80-110 ° С „5 2. A method according to claim 1, wherein the process is carried out in the presence of a catalyst, a weakly basic amine or an alkali metal acetate. 3. Method according to paragraphs. 1 and 2, characterized in that the process is conducted in an inert organic solvent medium. 6 4. A method according to claim 3, characterized in that benzene is used as an inert organic solvent. Sources of information taken into account during the examination 1. Post N. W. Interaction of chloral hydrate with aliphatic orthoesters. - “J. Org. Chem., 1941, No. 6, p. 830-835.