Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D211/00—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings
  • C07D211/04—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
  • C07D211/08—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms
  • C07D211/18—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D211/20—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms with hydrocarbon radicals, substituted by singly bound oxygen or sulphur atoms
  • C07D211/22—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with substituted hydrocarbon radicals attached to ring carbon atoms with hydrocarbon radicals, substituted by singly bound oxygen or sulphur atoms by oxygen atoms
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P37/00—Drugs for immunological or allergic disorders
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P37/00—Drugs for immunological or allergic disorders
  • A61P37/08—Antiallergic agents
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/42—Separation; Purification; Stabilisation; Use of additives
  • C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation

Definitions

• This invention relates to a novel process to obtain highly pure 4-(cyc!opropylcarbonyl)-c.. ⁇ - dimethylphenylacetic acid of Formula I through crystai ⁇ zation from a mixture of para and meta regioisomers of Formula I and II in cyclohexane. whereby the amount of undesired meta isomer.
• Formula I Formula H is decreased to below 0.5%.
• the compound of Formula 1 is a key intermediate for the preparation of high purity terfenadine carboxylate, which is a known antihistaminic.
• This invention relates to a process for the preparation of highly pure 4-(cycIopropylcarbonyl)- ⁇ , ⁇ - dimethylphenyiacetic acid of Formula I. a key intermediate useful in the preparation of highly pure Terfenadine carboxylate.
• Terfenadine carboxylate is a non-sedative antihistaminic compound. It is reported to be a specific ! l;-receptor antagonist that is also devoid of any anticholinergic, antiserotonincrgic, and antiadrenereic effects.
• halo is a halogen atom, such as. chlorine, bromine or iodine
• afkyl moiety has from 1 to 6 carbon atoms and is straight or branched, followed by reduction of the keto ⁇ e group and subsequent base hydrolysis.
• Preparation of compounds of Formula V is achieved by reacting ⁇ , ⁇ -dimethyiphenylacetic acid alkyl esters with 4-halobutyryl halide under general conditions of Fri ⁇ del-Crafts acyiation.
• Formula VII in the presence of aluminum chloride and the corresponding para acylated product has been obtained that contains no more than 10% of meta isomer.
• the presence of meta isomer at this stage results in an unacceptable level of meta isomer in terfenadine carboxylate and once again it is difficult to achieve pharmaceutically pure product from such a mixture. This requires time consuming purification processes which are wasteful of material and costly.
• US Patent 5,578,610 provides a procedure wherein the mixture of regioisomers of Formula VI has been transformed to another mixture of para and meta regioisomers of Formula VIII and
• US Patent 6.147.216 provides an alternate technique to obtain enriched para regioisomer by high vacmtm fracf mai disTrtlatrorr of mcthyi or ctfayl ester of the mixture of isomeric acids of Formula V1H followed by repeated fractional crys tUization at low temperatures. This process is operationally tedious, inefficient yields are tow and therefore, is not amenable to industrial scale.
• the aim of the present invention is to provide an efficient method to obtain highly pure 4-(c ⁇ clopropylcarbonyl)- ⁇ . -dimethyiphenylacelic acid of Formula I. which is an useful intermediate for the preparation of pharmaceutically highly pure antihistaminic piperidine derivatives.
• the instant invention relates to a novel process to produce highly pure para regioisomer, 4-(cyclopropylcarbonyl)- ⁇ , ⁇ -dimethylphenylacetic acid, of Formula I whereby the amount of meta isomer, 3-(cyclopropylcarbonyl)- ⁇ . ⁇ -dimethylphenylacef ⁇ c acid, of Formula II is decreased to below 0.5%.
• the present invention involves treating I ⁇ acetoxy-2-methyl ⁇ 2-phenylpropane, of Formula VII in methylene chloride with 4-chlorobutyryJ chloride and anhydrous aluminium chloride to obtain a mixture of regioisomers.
• of Formula IX that contains greater than 80% of para isomer.
• This mixture of regioisomers is hydrolyzed under conditions effective to produce a mixture of regioisomers of Formula X. Typically this reaction is carried out by a base hydrolysis procedure which is well known in the art. The intermediate hydroxy compound is then oxidized
• Formula V1U Mixture of para and meta regioisomers suitable acidic medium such as acetic acid / acetone at a temperature ranging from room temperature to 60°C.
• suitable reagents for the oxidation are, chromium (IV) oxide, sodium periodate, M-chloroperbenzoic acid and nitric acid.
• the above mixture of para and meta regioisomers of formula VIII is subjected to crystallization process to recover higMy pure para cegtoisomer of Formula I.
• Such recovery is carried out by selective crystallization from a suitable solvent that inc ude hexanes, heptane, cyclohexane, diethyl ether, di ⁇ sopropyl «J ⁇ r and a mixture thereof.
• a suitable solvent that inc ude hexanes, heptane, cyclohexane, diethyl ether, di ⁇ sopropyl «J ⁇ r and a mixture thereof.
• one may proceed preferably by using cyclohexane for crystallization.
• Selective crystallization is achieved by dissolving a mixture of regioisomers of Formula VIII containing up to 20% of meta regioisomer in a solvent at a temperature ranging from 20°C to reflux temperature of the solvent.
• the amount of solvent is at least 5 parts by volume per part of the mixture of regioisomers. Higher amounts of solvent and generally upto 20 parts by volume may be used.
• the aforesaid solution is then slowly cooled to 20-25°C and the desired para regioisomer is obtained in highly pure form as a free flowing crystalline material which is isolated by filtration.
• Substrate from the previous example 100 g. 0.45 mol was dissolved in acetone (300 ml) at 25-30°C. DM water (450 ml) and acetic acid (60 ml) were added. Potassium permanganate ( 153 g. 0.96 mol) was added in small lots in 2 hours maintaining the temperature at 25-3 ⁇ r C. Stirring was continued for 1 hour at 30-35°C and thereafter, temperature was raised to 40-45°. After stirring for 2 hours the reaction mass was filtered through hyflo and the residue was washed with acetone ( 100 ml). The filtrate was concentrated at 40-45°C under reduced pressure to remove acelonc.
• the mixture of regioisomers ( 100 g. 0.43 mol) obtained in accordance with F.xamplc 3 was dissolved in cyclohexane ( 1500 ml) at 60-65°C.
• the solution was seeded with 0.5 g of pure para regioisomer at 50-55°C and was cooled to 15- I C 'C slow h in 2 hours and during this period, the product crystallizes out. Stirring was continued at 15- I 8°C for 1 hour to complete crystallization.
• the product was filtered, washed with cyclohexane (2x25 ml) and dried under reduced pressure at 35-40°C to yield 72 g of highly pure crystalline para regioisomer.
• Acetate buffer pH 4.0 was prepared by adding 1.2 ml of acetic acid to 1000 ml water and pH adjusted to 4.0 with dilute aqueous ammonia.
• Example 3 Substrate of Example 3 (50 g, 0.21 mol) was dissolved in diisopropyl ether (60 ml) and diluted with cyclohexane (280 ml) at 15-20°C. The crystallized material was filtered and washed with cyclohexane (2x20 ml) to obtain para regioisomer. Yield: 30.7 g.
• Buffer of pH 2.5 was prepared by dissolving 1.17 g of 1 -octanesulphonic acid sodium salt and 1 ml of tricthylamine in 1000 ml water and pH adjusted to 2.5 with orthophosphoric acid.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Pharmacology & Pharmacy (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• General Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Immunology (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Animal Behavior & Ethology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Crystallography & Structural Chemistry (AREA)
• Pulmonology (AREA)
• Hydrogenated Pyridines (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=29765111

Family Applications (1)

Country Status (7)

Cited By (4)

Families Citing this family (3)

Citations (2)

• 2002
  • 2002-06-19 SK SK71-2003A patent/SK712003A3/sk unknown
  • 2002-06-19 WO PCT/IN2002/000135 patent/WO2003000658A1/en not_active Ceased
  • 2002-06-19 SI SI200220003A patent/SI21232A/sl not_active IP Right Cessation
  • 2002-06-19 EP EP02745778A patent/EP1401815A1/en not_active Withdrawn
  • 2002-06-19 JP JP2003507065A patent/JP2004521942A/ja active Pending
• 2003
  • 2003-01-17 BG BG107476A patent/BG107476A/bg unknown
  • 2003-07-02 US US10/612,637 patent/US6903232B2/en not_active Expired - Fee Related

Patent Citations (3)

Also Published As

Similar Documents

Legal Events