GB384156A - Process for the manufacture of aliphatic halogenated alcohols - Google Patents

Abstract

Halogenated aliphatic alcohols are manufactured by causing halogenated aliphatic aldehydes containing no carbon double bonds to react with halogen magnesium alcoholates, in the absence of any solvent or diluent, or in the presence of a solvent containing no hydroxy groups, and decomposing the condensation products formed by means of water which advantageously contains some mineral acid. When using a solvent containing no hydroxyl groups, a certain amount of alcohol may also be present. The halogen magnesium alcoholates are prepared by reacting upon a halogen magnesium alkyl compound with an alcohol. Advantageously they are prepared in ethereal solution and employed without isolation. Other suitable solvents are benzene, ligroin, and anisol. The reaction is preferably performed at room temperature but sometimes heating is advantageous for the completion of the reaction. Examples describe the production of: (1) tribromoethyl alcohol from tribromoacetaldehyde in ethereal solution by means of bromomagnesium ethylate (from ethyl magnesium bromide and ethyl alcohol); (2) trichloroethyl alcohol from trichloroacetaldehyde in ethereal solution by means of bromomagnesium isopropylate (from ethyl magnesium bromide and isopropyl alcohol): (3) tribromoethyl alcohol from tribromoacetaldehyde in ethereal solution by means of bromomagnesium isopropylate; (4) as in (3) but using the reaction product of ethylmagnesium bromide and hydrobenzoin in ethereal solution; (5) as in (3) but in the absence of any solvent; (6) b -dichloro-g -chlorobutyl alcohol from a -dichloro-b -chlorobutyric aldehyde in solution in benzene, ether or anisol, by means of bromomagnesium n-butylate (from propyl magnesium bromide and butyl alcohol); (7) dibromoethyl alcohol from dibromoacetaldehyde in ethereal solution by means of bromomagnesium isopropylate; chloroethyl alcohol similarly from chloroacetaldehyde.