Unlock instant, AI-driven research and patent intelligence for your innovation.

Phthalide preparing method

A technology of methylol benzoic acid and methyl benzoate, applied in the field of preparation of o-hydroxymethyl benzoic acid lactone, can solve the problems of environmental pollution, difficulty in production, and high processing cost

Active Publication Date: 2010-02-03
JIANGSU GENGYUN CHEM CO LTD
View PDF6 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The raw material price of this method is very high, and the environmental pollution is relatively serious in the production process
[0005] (2) chemical reduction method, with zinc-acetic acid etc. as reducing agent, phthalic anhydride is reduced to phthalide, although this method production process is simpler, can cause more serious environmental pollution problem
[0012] CN1884272A discloses a method for synthesizing phthalide by liquid-phase hydrogenation of phthalic anhydride. The supported nickel catalyst of this method needs to be calcined at 400-800°C for 2-8 hours, and reduced at 300-700°C for 1 ~10 hours, difficult to make catalyst
[0013] Although the phthalic anhydride hydrogenation method has good yield and product quality, and is relatively friendly to the environment, the catalyst used is relatively expensive and difficult to make. Higher cost, greater risk in industrialized production

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Phthalide preparing method
  • Phthalide preparing method
  • Phthalide preparing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] Example 1: Synthesis of phthalide

[0053] Reaction equation

[0054]

[0055] Feeding ratio:

[0056] Methyl o-methylbenzoate: azobisisobutyronitrile: phthalide=300:0.1:1.85(w / w) Feeding quantity:

[0057] raw material name

Quantity (g)

Content (%)

Molecular weight

Mole

Methyl o-methylbenzoate

1600

99

150.18

10.5

Azobisisobutyronitrile

0.5

99

164.21

0.003

Chlorine

About 360

99.5

71

5.0

[0058] Phthalide

10

99.5

134

[0059] Operation process:

[0060] Add 1600 g (99%, 10.0 mol) of o-methyl benzoate and 0.5 g of AIBN to a 2000ml clean and anhydrous reaction flask. The temperature is raised to 80°C with stirring, the stirring is stopped, and chlorine gas is introduced (exothermic reaction) The water outside the reaction flask is cooled, and the temperature is controlled between 80°C and 90°C. Gas chromatography is used for tracking analysis. (Strictly control the dichloride ≤ 1.5%, generally when the monochloride can reach about ...

Embodiment 2

[0062] Example 2: The synthesis of phthalide is basically the same as that of Example 1, with the following changes:

[0063] The added methyl o-methyl benzoate was 915 g of the effluent of Example 1 and the new 685 g. After the addition of 1.6 g of AIBN, 908 g of unreacted methyl o-methyl benzoate was distilled off after the completion of the chlorine passage to obtain crude benzene 613g of phthalide was added to the recrystallized methanol mother liquor of Example 1 to dissolve, and then cooled and recrystallized to obtain 547g of white phthalide with a content of ≥99% and a yield of 88.6%.

[0064] The methanol mother liquor from the second recrystallization is added to the distillation flask to remove the methanol under normal pressure. The residue is measured at 100℃. Then add 30% of the weight of methanol. Stir to cool and crystallize until it is cooled to -10℃. Filter , 34.5g of phthalide can be obtained, the content is ≥94%, and the total yield is ≥92%.

[0065] After the me...

Embodiment 3

[0066] Example 3: Synthesis of 5-bromophthalide

[0067] Reaction equation

[0068]

[0069] Feeding ratio:

[0070] Methyl 4-bromo-2-methylbenzoate: azobisisobutyronitrile: 5-bromophthalide = 300: 0.1: 1.85 (w / w) Feeding quantity:

[0071] raw material name

Quantity (g)

Content (%)

Molecular weight

Mole

Methyl 4-bromo-2-methylbenzoate

1620

99

229.07

7.0

Azobisisobutyronitrile

0.5

99

164.21

0.003

Chlorine

Approximately 215

99.5

71

3.0

5-bromophthalide

10

99.5

213

[0072] Operation process:

[0073] Add 1620g (99%, 10.0mol) of methyl 4-bromo-2-methylbenzoate and 0.5g of AIBN to a 2000l clean and anhydrous reaction flask. The temperature is raised to 80°C while stirring, the stirring is stopped, and chlorine gas is introduced. Exothermic reaction) The water outside the reaction flask is cooled, the temperature is controlled at 80℃~90℃, and gas chromatography is used for tracking analysis. (Strictly control the dichloride ≤ 1.5%, generally w...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
melting pointaaaaaaaaaa
refractive indexaaaaaaaaaa
Login to View More

Abstract

The invention relates to a phthalide preparing method. The compound of phthalide is shown in a formula (I), wherein R1, R2, R3 and R4 are the same or different and respectively independent hydrogens or halogens. The method comprises the following steps: (I) causing a formula (II) to react with chlorine in the presence of initiator 1 so as to obtain a mixture of the formula (II) and a formula (III); adopting a gas chromatogram tracking analyzing area normalization method; and stopping chlorine introduction when the amount of generated o-chloromethyl methyl benzoate of the formula (III) is 40-30percent; (2) causing the mixture of the formula (II) and the formula (III) to undergo heating and cyclization in the presence of initiator 2 and under a negative pressure so as to remove chloromethane; and (3) removing unreacted o-methyl methyl benzoate of the formula (II) by means of rectification under a negative pressure so as to obtain raw phthalide of the formula (I). The phthalide preparingmethod can be easily and suitably carried out in a standard experiment and a production container which do not have defined sizes. From the production view, the phthalide preparing method is more general than the high-pressure catalytic hydrogenation.

Description

Technical field [0001] The present invention relates to a preparation method of an intermediate of formula (I), specifically to a method used as an intermediate in the preparation of agricultural fungicides methoxyacrylates (such as kresoxim-methyl, trifloxystrobin) Preparation method of o-hydroxymethylbenzoic acid lactone (phthalide, 2-benzo[c]furanone) of the compound. Background technique [0002] Phthalide (o-hydroxymethyl benzoate lactone) English name: Phthalide, molecular formula C 8 H 6 O 2 , the pure product is needle-like or flaky crystals. The melting point is 75℃, 65.8℃ (unstable type), the relative density is 1.636 (99.1 / 4℃), and the refractive index is 1.536 (99.1℃). Soluble in alcohol, ether and hot water, very slightly soluble in cold water. Usage: Used as intermediate of fine chemicals. Used in the production of dye intermediates 1,4-dichloroanthraquinone, 1-chloroanthraquinone, anticoagulant drug phenylindanedione, anti-anxiety drug doxepin, agricultu...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/88
Inventor 于康平李泽方
Owner JIANGSU GENGYUN CHEM CO LTD