US3950356A
Expired / Lapsed
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Synthesis of photochromic indolinespiropyrans
Assignee: Saint Gobain Industries SA
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Filing: 1970-03-05
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Granted: 1976-04-13
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Expires: 1990-03-05
Abstract
Abstract Photochromic indolinespiropyrans are formed in a substantially pure state by the reaction of a 2-alkyleneindoline and an orthohydroxyl aromatic aldehyde dissolved in dimethylformamide.
Inventors
- 👤 Alain Hinnen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:30
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/685
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
46 words
A method for the synthesis of photochromic indolinespiropyrans by the condensation of a base of an alkylene-2-indoline and an orthohydroxyl-aromatic aldehyde, which comprises dissolving the aromatic aldehyde in dimethyl formamide, adding the indoline base to the solution and heating under reflux, and recovering the photochromic indolinespiropyran.
Claim 2
Independent Claim
46 words
A method for the synthesis of photochromic indolinespiropyrans by the condensation of a base of an alkylene-2-indoline and an orthohydroxyl-aromatic aldehyde, which comprises dissolving the aromatic aldehyde in dimethyl formamide, adding the indoline base to the solution and heating under reflux, and recovering the photochromic indolinespiropyran.
Claim 3
Dependent Claim
17 words
A method according to claim 1 in which the indolinespiropyran is recovered by crystallization from the dimethylformamide.
Claim 4
Dependent Claim
22 words
A method according to claim 1 in which the indolinespiropyran is recovered by the addition of an alcohol to the dimethylformamide solution.
Claim 5
Dependent Claim
13 words
A method according to claim 1 in which the indoline base is 1,3,3-trimethyl-2-methyleneindoline.
Claim 6
Dependent Claim
13 words
A method according to claim 1 in which the indoline base is 5-chloro-1,3,3-trimethyl-2-methyleneindoline.
Claim 7
Dependent Claim
15 words
A method according to claim 1 in which the orthohydroxyl aromatic aldehyde is a salicylaldehyde.
Claim 8
Dependent Claim
15 words
A method according to claim 1 in which the orthohydroxyl aromatic aldehyde is 5 nitrosalicylaldehyde.
Claim 9
Dependent Claim
17 words
A method according to claim 1 in which the orthohydroxyl aldehyde is a 2 hydroxyl 1 naphthaldehyde.
Claim 10
Dependent Claim
14 words
A method according to claim 8 in which the orthohydroxyl aromatic aldehyde is 2-hydroxyl-6-nitro-1-naphthaldehyde.
Claim 11
Independent Claim
19 words
A method for the preparation of 6'-nitro-5-chloro-1,3,3-trimethyl-indoline-2-spiro-2'-benzopyran which comprises dissolving 5-nitrosalicylaldehyde in dimethylformamide, adding 5-chloro-1,3,3-trimethyl-2-methyleneindoline and heating under reflux.
Claim 12
Independent Claim
19 words
A method for the preparation of 6'-nitro-5-chloro-1,3,3-trimethyl-indoline-2-spiro-2'-benzopyran which comprises dissolving 5-nitrosalicylaldehyde in dimethylformamide, adding 5-chloro-1,3,3-trimethyl-2-methyleneindoline and heating under reflux.
Claim 13
Independent Claim
19 words
A method for the preparation of 7'-nitro-1,3,3-indoline-2-spiro-2'-naphthopyran, which comprises dissolving 2-dihydroxy-6-nitro-1-naphthaldehyde in dimethylformamide, adding 1,3,3-trimethyl-2-methyleneindoline, and refluxing the mixture.
Claim 14
Independent Claim
19 words
A method for the preparation of 7'-nitro-1,3,3-indoline-2-spiro-2'-naphthopyran, which comprises dissolving 2-dihydroxy-6-nitro-1-naphthaldehyde in dimethylformamide, adding 1,3,3-trimethyl-2-methyleneindoline, and refluxing the mixture.
References Cited (Backward Citations)
FR1262318A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |