Synthesis method of (R) 4 (tert-butoxy) 2 (cyclopentyl methyl) 4 oxobutyric acid

Abstract

The invention belongs to the field of organic chemistry, and discloses a synthesis method of a compound (R) 4 (tert-butoxy) 2 (cyclopentyl methyl) 4 oxobutyric acid of which the formula 5 is shown in the description. According to the technical scheme, 3-cyclopentyl propionyl chloride is adopted as a raw material, through chiral prothetic group induction, an alkylation reaction and a hydrolysis reaction, the compound of which the formula 5 is shown in the description is prepared. According to the synthesis method of the compound (R) 4 (tert-butoxy) 2 (cyclopentyl methyl) 4 oxobutyric acid, by adjusting the temperatures in chiral prothetic group induction, the alkylation reaction and the hydrolysis reaction and the catalysts used in chiral prothetic group induction, the alkylation reaction and the hydrolysis reaction, the compound of which the formula 5 is shown in the description is synthesized with high yield. The path is short, the aftertreatment is simple, the total yield through the three-step reaction can reach 65%, and the optical purity can reach 95% or above.

Description

technical field

[0001] The present invention relates to a process improvement of a synthesis method of an important new compound, in particular to a synthesis method of (R)-4-(tert-butoxy)-2-(cyclopentylmethyl)-4-oxobutanoic acid , belonging to the field of organic chemistry. Background technique

[0002] The chemical name of compound (5) is (R)-4-(tert-butoxy)-2-(cyclopentylmethyl)-4-oxobutanoic acid, and its structural formula is as follows:

[0003]

[0004] Compound (5), as an important intermediate of various anticancer compounds and antibacterial compounds (such as peptide deformylase inhibitors), plays an important role in the research of antibacterial, anticancer and antimetabolic compounds. For example, in the research of antibacterial compounds, it is an important acid fragment of novel peptide deformylase inhibitors, an important intermediate in anticancer compounds, and an important component of cathepsin inhibitors. Its synthesis has been reported in existi...

Examples

Embodiment 1

[0052] The first step: the synthesis of formula (3) compound (S)-4-benzyl-3-(3-cyclopentylpropionyl)-2-oxazolidinone

[0053] Add compound (S)-4-benzyl-2-oxazolidinone (2) (150.0g, 0.85moL), 4-dimethylaminopyridine (155.1g, 1.27moL), triethyl Amine (128.60g, 1.27moL), dichloromethane (1500mL), cooled to 0-5°C in an ice-water bath, and compound 3-cyclopentylpropionyl chloride (1) (145.80g, 0.89moL) was added dropwise, and the temperature was controlled below 10°C, the dropwise addition was completed, and the reaction was continued for 4.0 hours, followed by TLC (developer: petroleum ether: ethyl acetate = 5:1), and the resulting solid was removed by filtration, and the filtrate was sequentially added to a saturated aqueous solution of sodium bicarbonate (500 mL ), 10% citric acid aqueous solution (2*500mL), washed with saturated brine (500mL), dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure to obtain a crude product, added n-heptane (300mL) fo...

Embodiment 2

[0062] Under the condition that the experimental environment is guaranteed and the experimental operation is basically the same, a series of screenings have been carried out on the solvent used in the first step reaction of Example 1, reaction temperature, alkali and catalyst, and its operation is the same as the first step in Example 1 operation, the filtered results are shown in Table 1 below:

[0063] Table 1

[0064]

Embodiment 3

[0066] Under the condition that the experimental environment is guaranteed and the experimental operation is basically the same, a series of screenings are carried out on the solvent used in the second step reaction of Example 1, reaction temperature, alkali and catalyst, and its operation is the same as the second step in Example 1 operation, the results are shown in Table 2 below:

[0067] Table 2

[0068]

[0069]

technical field

[0001] The present invention relates to a process improvement of a synthesis method of an important new compound, in particular to a synthesis method of (R)-4-(tert-butoxy)-2-(cyclopentylmethyl)-4-oxobutanoic acid , belonging to the field of organic chemistry. Background technique

[0002] The chemical name of compound (5) is (R)-4-(tert-butoxy)-2-(cyclopentylmethyl)-4-oxobutanoic acid, and its structural formula is as follows:

[0003]

[0004] Compound (5), as an important intermediate of various anticancer compounds and antibacterial compounds (such as peptide deformylase inhibitors), plays an important role in the research of antibacterial, anticancer and antimetabolic compounds. For example, in the research of antibacterial compounds, it is an important acid fragment of novel peptide deformylase inhibitors, an important intermediate in anticancer compounds, and an important component of cathepsin inhibitors. Its synthesis has been reported in existi...

Examples

Embodiment 1

[0052] The first step: the synthesis of formula (3) compound (S)-4-benzyl-3-(3-cyclopentylpropionyl)-2-oxazolidinone

[0053] Add compound (S)-4-benzyl-2-oxazolidinone (2) (150.0g, 0.85moL), 4-dimethylaminopyridine (155.1g, 1.27moL), triethyl Amine (128.60g, 1.27moL), dichloromethane (1500mL), cooled to 0-5°C in an ice-water bath, and compound 3-cyclopentylpropionyl chloride (1) (145.80g, 0.89moL) was added dropwise, and the temperature was controlled below 10°C, the dropwise addition was completed, and the reaction was continued for 4.0 hours, followed by TLC (developer: petroleum ether: ethyl acetate = 5:1), and the resulting solid was removed by filtration, and the filtrate was sequentially added to a saturated aqueous solution of sodium bicarbonate (500 mL ), 10% citric acid aqueous solution (2*500mL), washed with saturated brine (500mL), dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure to obtain a crude product, added n-heptane (300mL) fo...

Embodiment 2

[0062] Under the condition that the experimental environment is guaranteed and the experimental operation is basically the same, a series of screenings have been carried out on the solvent used in the first step reaction of Example 1, reaction temperature, alkali and catalyst, and its operation is the same as the first step in Example 1 operation, the filtered results are shown in Table 1 below:

[0063] Table 1

[0064]

Embodiment 3

[0066] Under the condition that the experimental environment is guaranteed and the experimental operation is basically the same, a series of screenings are carried out on the solvent used in the second step reaction of Example 1, reaction temperature, alkali and catalyst, and its operation is the same as the second step in Example 1 operation, the results are shown in Table 2 below:

[0067] Table 2

[0068]

[0069]

Images