US4399074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of tertiary alkyl isocyanates
Assignee: Wyeth Holdings LLC
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Filing: 1982-04-26
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Granted: 1983-08-16
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Expires: 2002-04-26
Abstract
Abstract A process for the production of tertiary alkyl isocyanates, such as tetramethylxylylene diisocyanates, is disclosed in which the corresponding tertiary alkyl halide is reacted with an alkali metal cyanate utilizing a zinc-pyridine complex as a catalyst which has been prereacted with the cyanate before reaction with the halide.
Inventors
- 👤 Frederic C. Schaefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:12
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
99 words
A process for production of a tertiary alkyl isocyanate from the corresponding tertiary alkyl halide which comprises: a. preparing a complex of a zinc salt of an acid selected from mineral acids and carboxylic acids and pyridine in a 1:2 mole ratio, b. thereafter reacting said zinc-pyridine complex with an alkali metal cyanate to form a zinc-pyridine-cyanate complex containing 2 equivalents of cyanate anion per atom of zinc, and c. reacting said zinc-pyridine-cyanate complex with said tertiary alkyl halide in an aprotic solvent at a temperature of from 0° C. to 100° C. to form said tertiary alkyl isocyanate.
Claim 2
Dependent Claim
99 words
A process for production of a tertiary alkyl isocyanate from the corresponding tertiary alkyl halide which comprises: a. preparing a complex of a zinc salt of an acid selected from mineral acids and carboxylic acids and pyridine in a 1:2 mole ratio, b. thereafter reacting said zinc-pyridine complex with an alkali metal cyanate to form a zinc-pyridine-cyanate complex containing 2 equivalents of cyanate anion per atom of zinc, and c. reacting said zinc-pyridine-cyanate complex with said tertiary alkyl halide in an aprotic solvent at a temperature of from 0° C. to 100° C. to form said tertiary alkyl isocyanate.
Claim 3
Dependent Claim
14 words
A process according to claim 1 in which said zinc salt is zinc chloride.
Claim 4
Dependent Claim
13 words
A process according to claim 2 in which said solvent is methylene dichloride.
Claim 5
Dependent Claim
14 words
A process according to claim 2 in which said halide is a di(2-chloroisopropyl)benzene dichloride.
Claim 6
Dependent Claim
15 words
A process according to claim 2 in which said halide is an α,α-dimethyl-isopropenyl benzyl chloride.
Claim 7
Dependent Claim
13 words
A process according to claim 2 in which said halide is a tris(2-chloroisopropyl)benzene.
Claim 8
Dependent Claim
13 words
A process according to claim 2 in which said halide is a di(2-chlorisopropyl)naphthalene.
Claim 9
Dependent Claim
13 words
A process according to claim 2 in which said halide is α,α-dimethylbenzyl chloride.
References Cited (Backward Citations)
US4130577A
Cited
US4224238A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |