Reductive alkylation of amine to make tertiary amino polyol as precursor of fabric softening esters

Abstract: The present invention describes an alternative reaction path for the making of quaternary ammonium esters for fabric softening. The process starts from a chloroepoxide which is reacted with ammonia and water to form a primary amino polyol. The process continues as reductive alkylation of the primary and then secondary amine with aldehydes to provide an intermediate tertiary amino polyol. The first part of the process is followed by the tradtional esterification and quaternisation steps known in the art for making quaternized ammonium fabric softening compounds.

Description: The present invention describes an alternative reaction path for the making of quaternary ammonium esters for fabric softening. The process starts from a chloroepoxide which is reacted with ammonia and water to form a primary amino polyol. The process continues as reductive alkylation of the primary and then secondary amine with aldehydes to provide an intermediate tertiary amino polyol. This first part of the process is followed by the traditional esterification and quaternisation steps known in the art for making quaternized ammonium fabric softening compounds. Background of the invention The closest prior art to the present invention is US patent 4,137,180 which teaches the production of the same quaternized ammonium esters as the present invention and their use in fabric softeners. The process to make these ammoniums has a different first part of the reaction route while the second part containing the esterification and quaternisation steps is identical. Hence the intermediate tertiary amino polyol of this prior art is provided by the alternative reaction of alkylation of a secondary amine with a chloroalkyl polyol by elimination of hydrochloric acid. This first part of the known, prior art process to make the desired fabric softening ammoniums shows low selectivity, and uses for example dimethylamine as the secondary amine which is known to be highly poisonous and difficult to handle and has to be made e.g. from ammonia and methylchloride. Therefore the problem underlying the present invention is to provide an alternative process of high selectivity and using less difficult to handle and obtain raw materials while possibly still utilizing the easy parts of the known process. Other patent disclosures include the US 3,342,840 disclosing the manufacture of a mono ester quaternary ammonium salt. US 4,696,771 describes a process for the preparation of amino alcohols or polyols by reaction of a secondary alcanol amine with a terminal epoxy compound for the manufacture of polyurethane. US patent 4,540,821 and 4,654,376 both relate to the preparation of amino polyols by use of phenol, ammonia and ethylene oxide together with formaldehyde. Resulting products are used in textile softening compositions but are neither quaternized nor do they contain ester links. Summary of the invention The invention relates to a process to provide a tertiary amino polyol of the formula (I) in which R 1 and R 2 independently are (C 1 - C 8 ) - alkyl; A is hydrogen or R 1 ; n is 1,2,3,4,5 or 6; i is 2,3,4,5 or 6 i + n is less than 9 if A is hydrogen and i + n is less than 8 if A is not hydrogen. This amino polyol is used as an intermediate compound for further esterification and quaternisation to produce a quaternized ammonium fabric softening compound of formula (II) by traditional process steps. in which R 1 , R 2 , n, A are as in formula (I); R3 is (C 1 - C 8 ) - alkyl or aryl; j and k are independently 0,1,2,3 or 4 and j + k = i - 2 ; R 4 and R 5 are independently (C 11 -C 23 ) - alkyl or alkenyl. X - is a suitable counterion e.g. those disclosed in US,4,137,180. The process to make the intermediate tertiary amino polyol comprises the two steps which distinguish the claimed invention from the prior art. The tertiary amino polyol is made by: a) - reacting a halogen-CH 2 -(C 2 -C 8 -alkyl)(1-3) epoxide or a halogen CH 2 (C 2-6 ) polyalcohol with ammonia and water to form a primary amino polyol; and b) - reductive alkylation of the resulting primary amino polyol with aliphatic (C 1 - C 8 ) - aldehydes to form the tertiary amino polyols of formula (I). Preferred embodiments of the process of the present invention are in accordance with the dependent claims. Examples In these examples the closest prior art (US 4,137,180) is compared with the present invention. For common conditions and reactions the details are therefore not given but can be referred to from prior art disclosures. According to the present invention a α-chlorohydrin is reacted in an aqueous environment with ammonia according to the reaction path: to result in a first intermediate mono amino polyol namely aminopropanediol while releasing hydrochloric acid. The mono amino polyol is then reacted using formic acid or catalytic hydrogen e.g. with palladium with formaldehyde in a stoichiometric mole ratio of aminopropanediol to formaldehyde of 1:2. The reaction results after full conversion in dimethylaminopropanediol which is the starting amine to produce a quaternized ammonium compound as disclosed in the prior art. The reaction path to make dimethylaminopropanediol is : It has no alternative product as a result, i.e. the selectivity is 100%. In the prior art US 4,137,180 the two process steps (to make the intermediate dimethylaminopropanediol) are given by the reaction paths and The second reaction has however the drawback that it may lead to stable side products namely quaternized dimethylammoniumdipropanediol, and by rearrangement to 2-dimethylaminopropanediol. These alternative reaction products of the reaction path b) reduces the process selectivity. Further it becomes necessary to eliminate the undesired process side products since they are not currently accepted as impurity in fabric softener compositions from a regulatory point of view in many countries. In addition the resulting fabric softener compounds from these side products have no known softening benefit and hence may reduces overall softening efficiency.

Claims: A process to provide a tertiary amino polyol of the formula (I) in which R 1 and R 2 independently are (C 1 - C 8 ) - alkyl ; A is hydrogen or R 1 ; n is 1,2,3,4,5 or 6; i is 2,3,4,5 or 6; i + n is less than 9 if A is hydrogen; and i + n is less than 8 if A is not hydrogen; said process being characterized in that the tertiary amino polyol is made by 2 steps: a) reacting a halogen-CH 2 -(C 2 -C 8 -alkyl) (1-3) epoxide or a halogen -CH 2 (C 2-6 ) poly-alcohol with ammonia and water to form a primary amino polyol; and b) reductive alkylation of the resulting primary amino polyol with aliphatic (C 1 -C 8 )-aldehydes to form the tertiary amino polyols of formula (I). A process according to claim 1 characterized in that i is 2; R 1 , R 2 , are independently (C 1 - C 2 ) - alkyl and A is a hydrogen. A process according to any of the preceding claims characterized in that the epoxide is an epichlorohydrin or the poly-alcohol is a α-chlorohydrin. A process according to any of the preceding claims characterized in that the reductive alkylation step b) uses catalytic hydrogen (palladium) or a chemical reducing agent, preferably formic acid. A process according to any of the preceding claims characterized in that the aldehyde in step b) is formaldehyde. A process according to claim 1, wherein said tertiary amino polyol is used as an intermediate compound for further esterification and quaternisation to produce a quaternized ammonium fabric softening compound of formula (II) in which R 1 , R 2 , n, i, A are as in formula (I); R3 is (C 1 - C 8 ) - alkyl or aryl; j and k are independently 0,1,2,3 or 4 and j + k = i - 2 ; R 4 and R 5 are independently (C 11 -C 23 ) - alkyl or alkenyl; and X - is a suitable counterion. A process according to claim 6, characterised in that R 1 , R 2 , R 3 are independently (C 1 -C 2 )-alkyl and A is hydrogen.

Inventors: HARDY FREDERICK EDWARD, HUBESCH BRUNO, SIMPSON ANTHONY J, HARDY, FREDERICK EDWARD, HUBESCH, BRUNO, SIMPSON, ANTHONY J.
Applicants: PROCTER & GAMBLE, THE PROCTER & GAMBLE COMPANY
Application year: 1993
Main classification: C07C215
IPC codes: C07B61, C07C213, B01J23, C07C215