US4742176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone
Assignee: FMC Corp
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Filing: 1986-02-14
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Granted: 1988-05-03
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Expires: 2006-02-14
Abstract
Abstract An improved process for the manufacture of herbicidal 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone by cyclizing 3-chloro-N-hydroxy-2,2-dimethylpropanamide with an alkaline or alkaline earth hydroxide at a pH of 7.5 to 9.5, benzylating the resulting 4,4-dimethyl-3-isoxazolidinone, eliminating by-product 1-[(2-chlorophenyl)methoxy]-3,3-dimethyl-2-azetidinone by contacting the product mixture with anhydrous hydrogen chloride, and further benzylating free isoxazolidinone with base.
Inventors
- 👤 Mariano A. Guiducci
- 👤 Matthew I. Levinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:40
CPC Classifications
C; C07; C07D; C07D261/00; C07D261/02; C07D261/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
A process for preparing an N-benzyl substituted isoxazolidinone, substantially free of azetidinone, which comprises (i) cyclizing a 3-chloro-N-hydroxypropanamide with a base selected from alkaline and alkaline earth hydroxides, while maintaining the pH in a range of 7.5 to 9.5; (ii) reacting the unisolated products of step i with a benzyl halide; (iii) isolating and dehydrating the non-aqueous phase products from the products of step ii; (iv) treating the products of step iii with at least 0.2 mole of anhydrous hydrogen chloride per mole of propanamide; and (v) continuously treating the unisolated products of step iv with sufficient base, selected from alkaline and alkaline earth hydroxides and carbonates, to maintain the pH in a range of 7.5 to 9.5, for a period of one to three hours.
Claim 2
Dependent Claim
126 words
A process for preparing an N-benzyl substituted isoxazolidinone, substantially free of azetidinone, which comprises (i) cyclizing a 3-chloro-N-hydroxypropanamide with a base selected from alkaline and alkaline earth hydroxides, while maintaining the pH in a range of 7.5 to 9.5; (ii) reacting the unisolated products of step i with a benzyl halide; (iii) isolating and dehydrating the non-aqueous phase products from the products of step ii; (iv) treating the products of step iii with at least 0.2 mole of anhydrous hydrogen chloride per mole of propanamide; and (v) continuously treating the unisolated products of step iv with sufficient base, selected from alkaline and alkaline earth hydroxides and carbonates, to maintain the pH in a range of 7.5 to 9.5, for a period of one to three hours.
Claim 3
Dependent Claim
13 words
A process of claim 1 in which the benzyl halide is 2-chlorobenzyl chloride.
Claim 4
Dependent Claim
21 words
A process of claim 1 in which the pH in step i is maintained in the range of 8.5 to 9.5.
Claim 5
Dependent Claim
11 words
A process of claim 1 in which the 3-chloro-N-hydroxypropanamide is 3-chloro-n-hydroxy-2,2-dimethylpropanamide.
Claim 6
Dependent Claim
99 words
A process for preapring 2-[(2-chlorophenyl)methyl)-4,4-dimethyl-3-isoxazolidinone which comprises, (i) cyclizing 3-chloro-N-hydroxy-2,2-dimethylpropanamide with sodium hydroxide, while maintaining the pH in a range of 7.5 to 9.5; (ii) reacting the unisolated products of step i with 2-chlorobenzyl chloride; (iii) isolating and dehydrating the non-aqueous phase products from the products of step ii; (iv) treating the product of step iii with anhydrous hydrogen chloride; and (v) continuously treating the unisolated products of step iv, with sufficient base selected from sodium carbonate and sodium hydroxide to maintain the pH in a range of 7.5 to 9.5, for a period of one to three hours.
Claim 7
Dependent Claim
99 words
A process for preapring 2-[(2-chlorophenyl)methyl)-4,4-dimethyl-3-isoxazolidinone which comprises, (i) cyclizing 3-chloro-N-hydroxy-2,2-dimethylpropanamide with sodium hydroxide, while maintaining the pH in a range of 7.5 to 9.5; (ii) reacting the unisolated products of step i with 2-chlorobenzyl chloride; (iii) isolating and dehydrating the non-aqueous phase products from the products of step ii; (iv) treating the product of step iii with anhydrous hydrogen chloride; and (v) continuously treating the unisolated products of step iv, with sufficient base selected from sodium carbonate and sodium hydroxide to maintain the pH in a range of 7.5 to 9.5, for a period of one to three hours.
References Cited (Backward Citations)
US2862001A
Cited
US3271415A
Cited
US3364110A
Cited
US3475485A
Cited
US4455430A
Cited
US4405357A
Cited
US4337197A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |