Organic compounds -- part of the class 532-570 series – Organic compounds – Nitriles
Reexamination Certificate
2000-03-21
2001-10-23
Powers, Fiona T. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitriles
C558S372000
Reexamination Certificate
active
06307086
ABSTRACT:
The invention relates to a process for preparing long-chain glycine-N,N-diacetic acid derivatives.
Glycine-N,N-diacetic acid derivatives can be employed as biodegradable completing agents for alkali metal and heavy metal ions.
Various processes for preparing these compounds are known.
WO 94/29421 describes processes for preparing glycine-N,N-diacetic acid derivatives. These entail converting long-chain aliphatic aldehydes with iminodiacetonitrile and HCN alkylglycinonitrile-N,N-diacetonitrile, the resulting compound being hydrolyzed. The compounds can likewise be obtained by reacting the aldehydes with HCN and ammonia to give substituted amino nitrites, which are hydrolyzed to substituted amino acids, which is followed by reaction with formaldehyde and sodium cyanide. The process is too complicated for some compounds because long reaction times are necessary. Moreover the yields of the required compounds are still in need of improvement. The proposed processes are not always suitable for transfer to the industrial scale.
DE-A 195 18 986 describes a process for preparing gly-cine-N,N-diacetic acid derivatives by reacting glycine derivatives or their precursors with formaldehyde and hydrogen cyanide or reacting iminodiacetonitrile or iminodiacetic acid with appropriate aldehydes and hydrogen cyanide in aqueous acidic medium. The starting material employed in this case is the unpurified crude material derived from the industrial synthesis of glycine derivatives or their precursors or of iminodiacetonitrile or iminodiacetic acid, or mother liquors produced in syntheses of these types. The process is carried out as indicated in WO 94/29421.
DE-A-195 18 187 relates to a process for preparing glycine-N,N-diacetic acid derivatives by reacting glycine derivatives or their precursors with formaldehyde and alkali metal cyanide in aqueous alkali medium. The process is likewise based on the process described in WO 94/29421, but firstly from 0.5 to 30% of the amount of alkali metal cyanide required for the reaction is added to the glycine derivatives or their precursors, and then the remaining amount of alkali metal cyanide and the formaldehyde are metered in simultaneously over a period of from 0.5 to 12 hours. Even this variant of the process cannot eliminate all the abovementioned disadvantages.
It is an object of the present invention to provide a process for preparing glycine-N,N-diacetic acid derivatives by reacting iminodiacetonitrile with aldehydes and HCN or alkali metal cyanides, which avoids the abovementioned disadvantages and is suitable for transfer to the industrial scale. The process ought to give high yields in short reaction times; it is additionally intended to provide alternative processes which avoid the abovementioned disadvantages.
We have found that this object is achieved by processes with several variants as described below by means of component steps. The glycine-N,N-diacetic acid derivatives can be obtained, for example, by reactions shown in the two reaction schemes detailed below.
The processes according to the invention are additionally explained by means of the reaction schemes depicted in the drawing, where
FIG. 1
shows reaction schemes A and B based on dode-canal as example and
FIG. 2
shows reactions schemes A1 and A2 for aldehydes of the formula R—CHO, where R has the meaning indicated hereinafter. The object is achieved in particular by a process for preparing compounds of the formula IIb
where R is C
6
-C
30
-alkyl or C
6
-C
30
-alkenyl, which may additionally have upto 5 hydroxyl groups, formyl groups, C
1
-C
4
-alkoxy groups, phenoxy groups or C
1
-C
4
-alkoxycarbonyl groups as substituents and may be interrupted by upto 5 nonadjacent oxygen atoms, or alkoxylate groups of the formula —(CH
2
)
k
—O—(A
1
O)
m
—(A
2
O)
n
—Y where A
1
and A
2
are, independently of one another, 1,2-alkylene groups having 2 to 4 carbon atoms, Y is hydrogen, C
1
-C
12
-alkyl, phenyl or C
1
-C
4
-alkoxycarbonyl, and k is 1, 2 or 3, and m and n are each numbers from 0 to 50, and the total of m+n must be at least 4,
by reacting iminodiacetonitrile with aldehydes of the formula R—CHO and HCN or alkali metal cyanides, the process being carried out
a) in the absence of an organic solvent and in the presence of a Lewis or Brönsted acid, or
b) in the presence or absence of an organic solvent and in the presence of an emulsifier, or
c) in the presence or absence of an organic solvent and under a pressure in the range from 1 to 40 bar.
It has been found according to the invention that is reactions with aldehydes and HCN or alkali cyanides, as well as the hydrolysis of nitriles or amides to acids, can be speeded up and, moreover, the yield is increased under an elevated pressure in the range from 1 to 40 bar, preferably from 1.5 to 30 bar, in particular from 2 to 15 bar. These preferred pressure ranges also relate to the other reactions mentioned. Reaction of iminodiacetonitrile with aldehydes and HCN can moreover be speeded up by reacting in the absence of an organic solvent and, in particular, in the absence of further water in the reaction system, ie. by reacting without diluent and in the presence of a Lewis or Brönsted acid.
The reaction can additionally be carried out in the presence of an emulsifier, which is preferably employed in a concentration of from 1 to 50 g/l, particularly preferably 2 to 30 g/l of reaction mixture. Emulsifiers which can be employed are all compounds suitable for this purpose. Examples are anionic, cationic, amphoteric and nonionic emulsifiers. The lipophilic end groups of the emulsifiers are, as a rule, straight-chain or branched alkyl radicals which may contain unsaturated bonds, aryl radicals or alkylaryl radicals. Examples of suitable hydrophilic end groups for anionic emulsifiers are carboxylate, sulfonate, sulfate, phosphate, polyphosphate, lactate, citrate and tartrate. Suitable examples of cationic emulsifiers are amine salts and quaternary ammonium compounds. Suitable amphoteric emulsifiers are zwitterionic compounds of the amino acid type and, for example, betaine. Suitable for nonionic emulsifiers are residues of alcohols, polyethers, glcyerol, sorbitol, pentaerythritol, sucrose, acidic acid or lactic acid. The emulsifiers may additionally have hydrophilic groups in between such as hydroxyl, ester, sulfamide, amide, polyamide, polyamine, amine, ether, polyether, glycerol, sorbitol, pentaerythritol or sucrose groups.
Examples of suitable emulsifiers are ethoxylation products and fatty acid condensation products, fatty alcohol ethoxylates and, where appropriate, polyglycols and products of the reaction of phenols and oils with ethylene oxide.
The emulsifiers particularly employed are compounds such as alkali metal alkyl sulfates, in particular sodium dodecyl sulfate or mixtures of hydrophobic alkyl sulfates. It is also possible to employ nonionic surfactants such as fatty alcohol ethoxylates, which are, in particular, low-foaming.
The process step indicated above relates to process B for converting the initial aldehyde into the compound of the formula IIb.
The invention also relates to a process for preparing compounds of the formula IIa
where R has the abovementioned meaning, by reacting aldehydes of the formula R—CHO with HCN or alkali metal cyanides and ammonia in the presence of an organic base, the reaction being carried out under a pressure in the range from 1 to 40 bar. In
FIG. 1
, this reaction corresponds to the conversion of the initial aldehyde into the compound of the formula IIa.
The invention likewise relates to a process for preparing compounds of the formula IIb as defined above, by reacting compounds of the formula IIa as are defined above and can be prepared by the above process, with formaldehyde and HCN or alkali metal cyanides, the process being carried out in the presence or absence of a solvent under a pressure in the range from 1 to 40 bar. This reaction corresponds to the step for converting the compound of the formula IIa into the compound of the formula IIb in FIG.
1
.
Braun Gerold
Detering Juergen
Greindl Thomas
Oetter Guenter
Oftring Alfred
BASF - Aktiengesellschaft
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Powers Fiona T.
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