GB778314A - Esters of hydroxyacetylenes carrying amino groups with substituted carbamic acids - Google Patents

Abstract

The invention comprises esters of amino ethynyl alcohols of the general formul : <FORM:0778314/IV(b)/1> <FORM:0778314/IV(b)/2> (wherein R1 and R2 each represent a straight or branched chain alkyl radical containing 1 to 6 carbon atoms, R3 is an alkyl radical containing 1 to 3 carbon atoms, R4 is an alkylene radical containing 1 to 4 carbon atoms and R5 and R6 are ethylene radicals) with carbamic acid substituted with an alkyl or phenyl group, and acid addition salts of said esters with organic or inorganic acids; and their preparation by esterification of the alcohols with an appropriately substituted organic isocyanate or carbamic acid chloride. This process may be combined with the preparation of the amino alcohol starting materials, by reacting the corresponding amino ketones not containing the ethynyl group with acetylene, preferably in the presence of an alkaline condensing agent such as sodium amide and preferably in an inert solvent, e.g. benzene or liquid ammonia. In examples: (1) the following ethynyl alcohols are prepared: 1-isopropyl-, 1-methyl-, 1-ethyl-, 1-n-propyl - and 1 - n - butyl - 4 - ethynyl - piperidol - 4 and 2 - dimethylaminomethyl - butynol-2, their hydrochlorides also being described; (2) 1 - methyl - 4 - ethynyl piperidol - 4 and phenyl isocyanate give 1-methyl-4-ethynylpiperidyl-4 phenyl carbamic acid ester; (3) 1-ethyl - 4 - ethynyl - piperidol - 4 and dimethylcarbamic acid chloride give 1-ethyl-4-ethynylpiperidyl-4 dimethylcarbamic acid ester. The hydrochlorides of the products of Examples (2) and (3) are described. The preparation of the following esters is also referred to, the first three from the appropriate isocyanates and the remainder from the appropriate carbamic acid chlorides: 1-ethyl-4-ethynyl-piperidyl-4 phenyl -, ethyl -, methyl -, diethyl -, dibutyl-and di-n-propyl-carbamic acid esters. The hydrochlorides of these esters are also described.