GB582764A - Production of acetylenic alcohols - Google Patents

Abstract

Acetylenic alcohols are produced by reacting chlorinated unsaturated organic compounds of the general formula <FORM:0582764/IV/1> wherein R is a hydrocarbon radical or a hydrogen atom, R2 is an alkylene radical, X is a halogen atom or a hydroxyl radical and n is a positive whole number or zero, with a solution of an oxide or hydroxide of an alkali metal or alkaline earth metal of less than 50 per cent concentration by weight. A preferred group of starting compounds is one in which the value of n is zero and these yield alpha acetylenic alcohols. The many vinyl type chlorhydroxy compounds suitable as starting material for this process may be typified by the following non-limiting examples: 1-methyl, alpha and beta chlor allyl alcohols; 1,1-dimethyl, alpha and beta chlor allyl alcohols; 3-chloro, buten-2-ol-1; 1-methyl, 1-hydroxy, 3-chloro-butene-2; 1,1-dimethyl, -1-hydroxy, 3-chlorobutene-2; and compounds represented by the subsequent formul in which n is a positive whole number. <FORM:0582764/IV/2> as well as their homologues and suitable substituted derivatives. When X represents a halogen atom in formul I and II, it is replaced by a hydroxy group through basic hydrolysis. Thus, 3-chlorocrotyl alcohol may be obtained from 1,3-dichlorobutene-2; 3-chloropentene-2ol-1 from 1,3-dichlorohexene-2; 2-chloropropene-2-ol-4 from 2,4-dichloropropene-2, &c. Propargyl alcohol can also be produced by this process from the fraction of the by-products boiling between 104 DEG C. and 157 DEG C. formed in the production of allyl chloride via the chlorination of propylene. This fraction contains several three carbon atom polychlorides which may be used as starting materials. It is desirable to withdraw the acetylenic alcohol as soon as formed, e.g. by conducting the reaction in a higher boiling solvent, thus in the production of propargyl alcohol, amyl alcohol and other high boiling alcohols and ethers may be used. A solvent which boils below 115 DEG C., for example dioxane, may, however, be used. In examples, 3-chlor allyl alcohol is refluxed with aqueous solutions of sodium hydroxide of 20 per cent, 10 per cent and 50 per cent concentration respectively. The propargyl alcohol formed is extracted with diisopropyl ether and the yield increases as the concentration of alkali decreases, but an excess of 50 per cent alkali can be used when the reaction time is short. Other solvents such as hydrocarbons which do not react with the reaction product, higher molecular weight alcohols, petroleum ether, methyl ethyl ether, methyl propyl ether, propyl isopropyl ether, &c. may also be used. The products may be used to obtain their metallic derivatives or they may be hydrated to give solvents. The Specification as open to inspection under Sect. 91 states that weaker basic acting compounds may be used under more strenuous reaction conditions. This subject-matter does not appear in the Specification as accepted.