Patent US4361518A successfully refreshed from Google Patents.
US4361518A
Expired / Lapsed
US
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Manufacture of isocyanates
Assignee: Wyeth Holdings LLC
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Filing: 1981-12-17
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Granted: 1982-11-30
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Expires: 2001-12-17
Abstract
Abstract A process for production of tertiary benzyl isocyanates by reaction at low temperatures of the corresponding halides with an excess of isocyanic acid.
Inventors
- 👤 Balwant Singh
- 👤 William A. Henderson, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:17
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
92 words
A process for the production of tertiary benzyl isocyanates which comprises reacting a halide of the formula ##STR4## in which X represents a halogen atom, R 1 and R 2 represent alkyl groups of 1 to 3 carbon atoms and R 3 represents an aromatic group such as a phenyl, bisphenyl or naphthyl group or a substituted phenyl, biphenyl or naphthyl group having halogen, methyl, methoxy substituents or substituents of the formula ##STR5## with a stoichiometric excess of isocyanic acid in a solution in a solvent for said halide and isocyanic acid.
Claim 2
Dependent Claim
92 words
A process for the production of tertiary benzyl isocyanates which comprises reacting a halide of the formula ##STR4## in which X represents a halogen atom, R 1 and R 2 represent alkyl groups of 1 to 3 carbon atoms and R 3 represents an aromatic group such as a phenyl, bisphenyl or naphthyl group or a substituted phenyl, biphenyl or naphthyl group having halogen, methyl, methoxy substituents or substituents of the formula ##STR5## with a stoichiometric excess of isocyanic acid in a solution in a solvent for said halide and isocyanic acid.
Claim 3
Dependent Claim
33 words
A process according to claim 1 in which said reaction is carried out in the presence of a catalyst effective to promote the reaction of halide and isocyanic acid to form the isocyanate.
Claim 4
Dependent Claim
14 words
A process according to claim 2 in which the catalyst is a zinc salt.
Claim 5
Dependent Claim
13 words
A process according to claim 2 in which the catalyst is zinc chloride.
Claim 6
Dependent Claim
13 words
A process according to claim 2 in which the catalyst is zinc octanoate.
Claim 7
Dependent Claim
12 words
A process according to claim 1 in which the solvent is toluene.
Claim 8
Dependent Claim
12 words
A process according to claim 3 in which the solvent is toluene.
Claim 9
Dependent Claim
13 words
A process according to claim 1 in which the halide is a di(2-chloroisoproypl)benzene.
Claim 10
Dependent Claim
13 words
A process according to claim 3 in which the halide is a di(2-chloroisopropyl)benzene.
Claim 11
Dependent Claim
17 words
A process according to claim 1 in which the reaction temperature is between -10° and 10° C.
Claim 12
Dependent Claim
17 words
A process according to claim 3 in which the reaction temperature is between -10° and 10° C.
Claim 13
Dependent Claim
25 words
A process according to claim 1 in which the proportion of isocyanic acid is from 2 to 10 moles per halogen atom of the halide.
Claim 14
Dependent Claim
25 words
A process according to claim 3 in which the proportion of isocyanic acid is from 2 to 10 moles per halogen atom of the halide.
Claim 15
Dependent Claim
13 words
A process according to claim 1 in which the solvent is methylene dichloride.
Claim 16
Dependent Claim
13 words
A process according to claim 3 in which the solvent is methylene dichloride.
Claim 17
Dependent Claim
14 words
A process according to claim 5 in which the halide is para di(2-chloroisopropyl) benzene.
Claim 18
Dependent Claim
14 words
A process according to claim 5 in which the halide is meta di(2-chloroisopropyl) benzene.
References Cited (Backward Citations)
US3290350A
Cited
US4130577A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-29 | 1986-05-31 | 1986-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-29 | 1990-05-31 | 1990-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-29 | 1994-05-31 | 1994-11-30 | $7700.00 | Window Closed / Lapsed |