Patent GB-707293-A (GB)
Title: New substituted ethanolamines and the production thereof
Filed: 1950-07-19
Abstract: The invention comprises substituted ethanolamines of the formula <FORM:0707293/IV (b)/1> in which R represents a straight or branched chain aliphatic residue containing from two to six carbon atoms such as -CH2.CH2-, -CH2.CH2.CH2- <FORM:0707293/IV (b)/2> and <FORM:0707293/IV (b)/3> wherein the right-hand benzene nucleus may be substituted by one or more alkyl radicals, and acid addition salts thereof.  It comprises also the preparation of these compounds by catalytic hydrogenation of the corresponding ketones; or by saponifying a compound of the formula <FORM:0707293/IV (b)/4> where R1 is the residue of a sulphonic acid, or heating a compound of this general formula where R1 is a benzyl or alkylbenzyl residue with acid or hydrogenating it with a palladium catalyst; or by hydrogenation with a palladium catalyst of a compound of the formula <FORM:0707293/IV (b)/5> or by catalytic hydrogenation of mixtures of noradrenaline or noradrenalone or dibenzyl ethers or acid addition salts thereof with aralkyl aldehydes or ketones or by similar treatment of mixtures of 3 : 4-dihydroxyphenylglyoxal or dibenzyl ethers thereof with aralkylamines, the hydrogenation being effected in the presence of palladium catalysts in all cases where dibenzyl ethers are employed.  The products may be separated into optical isomers by known methods.  In examples: (1) 1-(31 : 41-dihydroxyphenyl) - 2 - (beta - phenylethylamino) - 1 - keto - ethane is hydrogenated to 1 - (31 : 41 - dihydroxyphenyl) - 2 - beta - phenylethylamino) - ethanol - 1; (2) 1 - (31 : 41 - dihydroxyphenyl) - 2 - (gamma - phenylpropylamino)-ethanol-1 is prepared by the method of (1); (3) 1-(31 : 41-dibenzyloxyphenyl)-2-(gamma-phenylpropylamino)-1-keto ethane is hydrogenated with a palladium catalyst to give the product of (2); (4) 1-(31 : 41-dihydroxyphenyl) - 2 - (alpha - methyl - gamma - phenylpropylamino) - 1 - keto - ethane is hydrogenated to 1 - (31 : 41 - dihydroxyphenyl) - 2 - (alpha - methyl - gamma - phenylpropylamino) - ethanol-1 which may be separated into stereoisomers; (5) 1-(31 : 41 - dibenzyloxyphenyl)-2-(alpha - methyl - gamma - phenylpropylamino) - ethanol-(1) is hydrogenated with a palladium catalyst to give the product of (4); (6) 1-(31 : 41 - dihydroxyphenyl) - 2 - (beta - phenylethylamino)-ethanol-(1-) esterified at the phenolic hydroxy groups by toluene sulphonic acid residues is hydrolysed; (7) a mixture of noradrenalone and hydrocinnamic aldehyde is hydrogenated to give the product of (2) and (8) a mixture of 3 : 4-dihydroxyphenyl-glyoxaldibenzyl ether and 1-phenyl-3-amino butane is hydrogenated to give the product of (4). 3 : 4-Dihydroxyphenylglyoxal dibenzyl ether is prepared by oxidation (selenium dioxide) of aceto-pyrocatechin dibenzyl ether.  1 - (31 : 41 - Dibenzyloxyphenyl) - 2 - (alpha - methyl - gamma - phenylpropylamino) - ethanol - 1 is prepared by reacting omega-bromoacetopyrocatechin dibenzyl ether with 1-phenyl-3-amino-butane and hydrogenating the resultant 1 - (3 : 4 - dibenzyloxyphenyl) - 2 - (alpha - methyl - gamma - phenylpropylamino) - 1 - ketoethane.  1 - (31 : 41 - Di - toluene - sulphonyloxyphenyl) - 2 - (beta - phenylethylamino - ethanol - (1) is prepared by brominating the ditoluene-sulphonic ester of aceto-pyrocatechin, reacting the resulting bromo compound with beta-phenylethylamine and reducing the resultant ditoluenesulphonic ester of 1-(31 : 41-dihydroxyphenyl)-2-(beta-phenylethylamino)-1-keto-ethane. Specification 707,360 is referred to.