US3988367A
Expired / Lapsed
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Preparation of N,N'-dicarboxymethyl-1,3-propanediamines
Assignee: WR Grace and Co
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Filing: 1975-11-11
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Granted: 1976-10-26
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Expires: 1995-11-11
Abstract
Abstract N,N'-Dicarboxymethyl-1,3-propanediamine (designated PDDA) is prepared by reacting 1,3-propanediamine with formaldehyde and HCN to form hexahydropyrimidine-1,3-diacetonitrile, which is hydrolyzed with an aqueous alkali metal hydroxide to form dialkali metal hexahydropyrimidine-1,3-diacetate which, in turn, is reacted with mineral acid to form the desired PDDA and formaldehyde. N,n'-dicarboxymethyl-2-hydroxy-1,3-propanediamine (designated HYDROXY-PDDA) is prepared by reacting 1,3-diamino-2-propanol with formaldehyde and HCN to form 5-hydroxyhexahydropyrimidine-1,3-diacetonitrile, which is hydrolyzed with an aqueous alkali metal hydroxide to form dialkali metal 5-hydroxyhexahydropyrimidine-1,3-diacetate which, in turn, is reacted with acid to form the desired HYDROXY-PDDA and formaldehyde.
Inventors
- 👤 Roger Robert Gaudette
- 👤 John Leonard Ohlson
- 👤 Patricia Marie Scanlon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:52
CPC Classifications
C; C07; C07D; C07D239/00; C07D239/02; C07D239/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
216 words
A process for forming an acid selected from a first group consisting of ##EQU1## and ##EQU2## comprising: a. forming a nitrile selected from a second group consisting of ##EQU3## and ##EQU4## by admixing, in an aqueous medium formaldehyde; (i) a member selected from a third group consisting of HCN and glycolonitrile; and (ii) a member selected from a fourth group consisting of 1,3-propanediamine and 1,3-diamino-2-propanol, to form a resulting admixture and maintaining the resulting admixture at a temperature effective for forming the second group member for a time effective for forming the second group member, the formaldehyde, the third group member, and the fourth group member being admixed in amounts effective for forming the second group member; b. hydrolyzing the nitrile in an aqueous medium with an amount of an alkali metal hydroxide or an alkaline earth metal hydroxide effective for hydrolyzing the nitrile to form a salt selected from a fifth group consisting of ##EQU5## and ##EQU6## in which M is an alkai metal ion or 1/2 of an alkaline earth metal ion; and c. converting the fifth group member to the first group member by treating the fifth group member in an aqueous medium with an amount of a mineral acid or an acidic ion exchange resin effective for forming the first group member.
Claim 2
Dependent Claim
216 words
A process for forming an acid selected from a first group consisting of ##EQU1## and ##EQU2## comprising: a. forming a nitrile selected from a second group consisting of ##EQU3## and ##EQU4## by admixing, in an aqueous medium formaldehyde; (i) a member selected from a third group consisting of HCN and glycolonitrile; and (ii) a member selected from a fourth group consisting of 1,3-propanediamine and 1,3-diamino-2-propanol, to form a resulting admixture and maintaining the resulting admixture at a temperature effective for forming the second group member for a time effective for forming the second group member, the formaldehyde, the third group member, and the fourth group member being admixed in amounts effective for forming the second group member; b. hydrolyzing the nitrile in an aqueous medium with an amount of an alkali metal hydroxide or an alkaline earth metal hydroxide effective for hydrolyzing the nitrile to form a salt selected from a fifth group consisting of ##EQU5## and ##EQU6## in which M is an alkai metal ion or 1/2 of an alkaline earth metal ion; and c. converting the fifth group member to the first group member by treating the fifth group member in an aqueous medium with an amount of a mineral acid or an acidic ion exchange resin effective for forming the first group member.
Claim 3
Dependent Claim
20 words
The process of claim 1 in which the fourth group member is 1,3-propanediamine and the first group member is ##STR65##
Claim 4
Dependent Claim
57 words
The process of claim 2 in which the first group member is precipitated from the aqueous medium in which the first group member is formed by admixing an amount of an alcohol selected from a sixth group consisting of methyl alcohol, ethyl alcohol, and isopropyl alcohol effective to precipitate the first group member with said aqueous medium.
Claim 5
Dependent Claim
14 words
The process of claim 3 in which the sixth group member is methyl alcohol.
Claim 6
Dependent Claim
39 words
The process of claim 1 in which the resulting admixture formed by admixing formaldehyde, the third group member and the fourth group member is prepared at 45°-70° C and maintained at said temperature to form the second group member.
Claim 7
Dependent Claim
14 words
The process of claim 1 in which the alkali metal hydroxide is sodium hydroxide.
Claim 8
Dependent Claim
15 words
The process of claim 1 in which the hydrolysis is conducted at the boiling point.
Claim 9
Dependent Claim
20 words
The process of claim 7 in which boiling is continued until the aqueous medium is substantially free of by-product ammonia.
Claim 10
Dependent Claim
25 words
The process of claim 1 in which the acid used to convert the fifth group member to the first group member is a mineral acid.
Claim 11
Dependent Claim
13 words
The process of claim 9 in which the mineral acid is hydrochloric acid.
Claim 12
Dependent Claim
35 words
The process of claim 10 in which an aqueous solution of the fifth group member is treated with an amount of hydrochloric acid effective for precipitating a hydrochloride salt having the formula ##STR66## or ##STR67##
Claim 13
Dependent Claim
14 words
The process of claim 11 in which the hydrochloride salt has the formula ##STR68##
Claim 14
Dependent Claim
13 words
The process of claim 9 in which the mineral acid is sulfuric acid.
Claim 15
Dependent Claim
34 words
The process of claim 13 in which an aqueous solution of the fifth group member is treated with an amount of sulfuric acid effective for precipitating a salt having the formula ##STR69## or ##STR70##
Claim 16
Dependent Claim
13 words
The process of claim 14 in which the salt has the formula ##STR71##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-26 | 1980-04-26 | 1980-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-26 | 1984-04-26 | 1984-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-26 | 1988-04-26 | 1988-10-26 | $7700.00 | Window Closed / Lapsed |