Disclosure of Invention
The technical problem to be solved by the invention is to provide a preparation method of a ketorolac intermediate (a compound shown in a formula I) so as to react at a lower temperature and avoid the product from darkening.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a synthesis method of ketorolac intermediate is carried out by reacting 1H-pyrrole-2-yl-phenyl ketone with 1,2-dichloroethane and potassium carbonate, adding NaY type molecular sieve into reaction system, reacting at 0-40 deg.C to obtain ketorolac intermediate as shown in formula I;
preferably, the temperature range is 20 to 30 ℃.
Preferably, the dosage of the NaY molecular sieve is 0.1 to 2.0 times of the total weight of the 1H-pyrrole-2-yl-phenyl ketone; more preferably from 0.1 to 0.5 times the total weight of 1H-pyrrol-2-yl-phenyl methanone.
Preferably, the silicon-aluminum ratio of the NaY molecular sieve is 4.5-5.0.
Preferably, the reaction time is 1 to 6 hours.
Preferably, the mass to volume ratio of 1H-pyrrol-2-yl-phenyl methanone to 1,2-dichloroethane is 1 g.
The invention can be matched with stirring in the reaction process, and has no special requirement on the stirring speed.
The reaction of the present invention has the following formula:
as a preferred embodiment of the present invention: dissolving 1H-pyrrole-2-yl-phenyl ketone (50g, 0.292mol) in 300ml of 1,2-dichloroethane, adding potassium carbonate (40.35g, 0.292mol), adding 5g to 100g of NaY molecular sieve, stirring the mixture at the temperature of 0 to 40 ℃, monitoring the reaction by using TLC (thin layer chromatography), filtering the potassium carbonate and the NaY molecular sieve until the raw material spots disappear, concentrating the filtrate under reduced pressure to dryness, adding 100ml of ethyl acetate and 100ml of n-heptane, heating to clear solution, cooling to below 25 ℃ for crystallization, filtering and drying to obtain the compound of the formula I. ESI-MS (+) =234.2m/z.
As a more preferred embodiment of the present invention: dissolving 1H-pyrrole-2-yl-phenyl ketone (50g, 0.292mol) in 300ml of 1,2-dichloroethane, adding potassium carbonate (40.35g, 0.292mol), adding 5g to 25g of NaY molecular sieve, stirring the mixture at the temperature of 20 to 30 ℃, monitoring the reaction by using TLC (thin layer chromatography), filtering the potassium carbonate and the NaY molecular sieve until the raw material spots disappear, concentrating the filtrate under reduced pressure to dryness, adding 100ml of ethyl acetate and 100ml of n-heptane, heating to clear, cooling to below 25 ℃ for crystallization, filtering and drying to obtain the compound of the formula I. ESI-MS (+) =234.2m/z.
The developing agent for monitoring the reaction by TLC is ethyl acetate, petroleum ether (v/v) =1:1, and a GF254 silica gel plate is used for observation under an ultraviolet lamp.
Has the advantages that: the invention discloses a synthesis method of ketorolac intermediate, which is characterized in that under the condition that potassium carbonate is used as alkali, 1H-pyrrole-2-yl-phenyl ketone and 1,2-dichloroethane are added with NaY molecular sieve to obtain the intermediate shown in formula I. In addition, the ketorolac has a long conjugated system, and is easy to generate colored impurities when heated at high temperature, so the color of the ketorolac is a key quality index of the product. Compared with the prior art, the method can reduce the requirement on reaction temperature and avoid the generation of colored impurities under the high-temperature condition.
Detailed Description
The present invention will be further explained with reference to specific examples, but the present invention is not limited to the following examples. The method is a conventional method if not specifically indicated. The solvent, materials and reagents used are all common reagents which are obtained from public commercial sources.
The NaY molecular sieves used in the following examples were obtained from Lian Hai Xin chemical Co., ltd. And had a silica to alumina ratio of 4.5 to 5.0. Comparative example 1:
the compounds of formula I are prepared according to the methods in J.Pharmacochem. 2002,12 (4): 228-229,232.
1H-pyrrol-2-yl-phenyl methanone (8.5g, 0.05mol), potassium carbonate (30g, 0.22mol), tetrabutylammonium bromide (1.6g, 5 mmol) were added to a reaction flask, 120ml of 1,2-dichloroethane were added, the mixture was stirred for reaction for 2 hours, cooled to room temperature, insoluble matter was filtered off, and the filtrate was concentrated to dryness under reduced pressure to give the compound of formula I (oil).
Comparative example 2:
the compound of formula I was prepared according to the method disclosed in chinese patent 202110177675.3.
1H-pyrrol-2-yl-phenyl methanone (15.0 g, 0.087mol), potassium carbonate (53.0 g,0.386 mol), tetrabutylammonium bromide (7.0 g, 22mmol) were added to a reaction flask, 300ml of 1, 2-dichloroethane was added, stirred and heated to reflux for 4 hours, reacted, cooled to room temperature, filtered, and the filtrate was concentrated to give the compound of formula I (oil).
Comparative example 3:
17ml of ethyl acetate and 17ml of n-heptane were added to the compound of formula I obtained in comparative example 1 as a brown oil, which was heated to clear, cooled to below 25 ℃ for crystallization, filtered and dried to give the compound of formula I as a light brown solid in a total amount of 7.8g, 67% yield.
Comparative example 4:
the compound of formula I obtained in comparative example 2 as a brown oil was added with 30ml of ethyl acetate and 30ml of n-heptane, heated to clear, cooled to below 25 ℃ for crystallization, filtered and dried to give the compound of formula I as a light brown solid in a total amount of 15.0g with a yield of 74%.
Example 1:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 5g NaY molecular sieve was added, the mixture was stirred at 25 ℃, the reaction was monitored by TLC, after 2 hours the material spots disappeared, potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heating was allowed to clear, cooling was cooled to below 25 ℃ for crystallization, filtration, and drying gave the compound of formula I as an off-white solid, 64.2g total, 94% yield.
Example 2:
1H-pyrrol-2-yl-phenyl methanone (150g, 0.88mol) was dissolved in 900ml 1,2-dichloroethane, potassium carbonate (121.1g, 0.88mol) was added, 75g NaY molecular sieve was added, the mixture was stirred at 0 deg.C, the reaction was monitored by TLC, after 4 hours the material spot disappeared, potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 300ml ethyl acetate and 300ml n-heptane were added, heating to clear, cooling to below 25 deg.C for crystallization, filtration, and drying to give the compound of formula I as an off-white solid, total 186.3g, 91% yield.
Example 3:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 50g of NaY molecular sieve was added, the mixture was stirred at 40 ℃, the reaction was monitored by TLC, after 1 hour the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in total 64.8g, yield 95%.
Example 4:
dissolving 1H-pyrrol-2-yl-phenyl methanone (250g, 1.46mol) in 1500ml 1,2-dichloroethane, adding potassium carbonate (201.8g, 1.46mol), adding 375g NaY molecular sieve, stirring the mixture at 20 ℃, monitoring the reaction by TLC, after 3 hours the raw material spots disappear, filtering off the potassium carbonate and NaY molecular sieve, concentrating the filtrate under reduced pressure to dryness, adding 500ml ethyl acetate and 500ml n-heptane, heating to clear, cooling to below 25 ℃ for crystallization, filtering, drying to obtain the compound of formula I as an off-white solid with total 317.4g and 93% yield.
Example 5:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 100g of NaY molecular sieve was added, the mixture was stirred at 30 ℃, the reaction was monitored by TLC, after 2 hours the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in total 66.2g, 97% yield.
Example 6:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml of 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 10g of NaY molecular sieve was added, the mixture was stirred at 20 ℃, the reaction was monitored by TLC, after 3 hours the spots of the raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml of ethyl acetate and 100ml of n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid, total 61.4g, yield 90%.
Example 7:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 10g of NaY molecular sieve was added, the mixture was stirred at 25 ℃, the reaction was monitored by TLC, after 3 hours the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in a total of 62.8g, 92% yield.
Example 8:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 20g of NaY molecular sieve was added, the mixture was stirred at 20 ℃, the reaction was monitored by TLC, after 3 hours the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in total 62.1g, 91% yield.
Example 9:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 25g of NaY molecular sieve was added, the mixture was stirred at 25 ℃, the reaction was monitored by TLC, after 4 hours the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in total 62.1g, 91% yield.
Example 10:
dissolving 1H-pyrrol-2-yl-phenyl ketone (60g, 0.35mol) in 360ml 1,2-dichloroethane, adding potassium carbonate (48.4 g, 0.35mol), adding 6g of NaY molecular sieve, stirring the mixture at 25 ℃, monitoring the reaction by TLC, after 4 hours the raw material spots disappear, filtering off the potassium carbonate and NaY molecular sieve, concentrating the filtrate under reduced pressure to dryness, adding 120ml ethyl acetate and 120ml n-heptane, heating to clear, cooling to below 25 ℃ for crystallization, filtering, and drying to obtain the compound of formula I as an off-white solid with a total yield of 76.2g and 93%.
Example 11:
1H-pyrrol-2-yl-phenyl methanone (70g, 0.41mol) was dissolved in 420ml 1,2-dichloroethane, potassium carbonate (56.5 g, 0.41mol) was added, 7g of NaY molecular sieve was added, the mixture was stirred at 25 ℃, the reaction was monitored by TLC, after 4 hours the spots of raw material disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 140ml ethyl acetate and 140ml n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid in a total of 85.0g, 89% yield.
Example 12:
dissolving 1H-pyrrol-2-yl-phenyl ketone (80g, 0.47mol) in 480ml 1,2-dichloroethane, adding potassium carbonate (64.6 g, 0.47mol), adding 80g of NaY molecular sieve, stirring the mixture at 25 ℃, monitoring the reaction by TLC, after 2 hours the raw material spots disappear, filtering off the potassium carbonate and NaY molecular sieve, concentrating the filtrate under reduced pressure to dryness, adding 160ml ethyl acetate and 160ml n-heptane, heating to clear, cooling to below 25 ℃ for crystallization, filtering, and drying to obtain the compound of formula I as an off-white solid with a total yield of 92.8g and 85%.
Example 13:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml of 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 60g of NaY molecular sieve was added, the mixture was stirred at 40 ℃, the reaction was monitored by TLC, after 2 hours the raw material spots disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml of ethyl acetate and 100ml of n-heptane were added, heated to clear, cooled to below 25 ℃ for crystallization, filtered, and dried to give the compound of formula I as an off-white solid, total 63.5g, 93% yield.
Example 14:
1H-pyrrol-2-yl-phenyl methanone (50g, 0.29mol) was dissolved in 300ml 1,2-dichloroethane, potassium carbonate (40.4 g, 0.29mol) was added, 5g NaY molecular sieve was added, the mixture was stirred at 0 deg.C, the reaction was monitored by TLC, after 6 hours the raw material spots disappeared, the potassium carbonate and NaY molecular sieve were filtered off, the filtrate was concentrated to dryness under reduced pressure, 100ml ethyl acetate and 100ml n-heptane were added, heating was allowed to clear, cooling was cooled to below 25 deg.C for crystallization, filtration, and drying gave the compound of formula I as an off-white solid in total 64.2g, 94% yield.
Example 15: color of the Compound of formula I
1g of the compound of the formula I is taken and placed in a 20ml volumetric flask and the volume is determined with dichloromethane. The solution is taken and placed in an ampoule and is compared with the yellow standard colorimetric solution in Chinese pharmacopoeia. The results are shown in Table 1.
TABLE 1
Sample numbering
|
Colour(s)
|
Comparative example 1
|
Number 6
|
Comparative example 2
|
Number 6
|
Comparative example 3
|
Number 4
|
Comparative example 4
|
Number 5
|
Example 1
|
Number 2
|
Example 2
|
Number 1
|
Example 3
|
Number 1
|
Example 4
|
Number 2
|
Example 5
|
Number 2
|
Example 6
|
Number 1
|
Example 7
|
Number 1
|
Example 8
|
Number 2
|
Example 9
|
Number 1
|
Example 10
|
Number 1
|
Example 11
|
Number 1
|
Example 12
|
Number 1
|
Example 13
|
Number 1
|
Example 14
|
Number 1
|
Example 15
|
Number 1 |
The test results show that the colour of the samples prepared using the present invention is significantly lighter than that of the samples obtained in the comparative examples.
The present invention provides a method and a concept for synthesizing ketorolac intermediate, and a method and a way for implementing the technical scheme are many, and the above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention. All the components not specified in the present embodiment can be realized by the prior art.