Patent GB-587275-A (GB)
Title: Improvements relating to the production of secondary and tertiary halogenated alcohols
IPC: C07C31/34
Filed: 1944-03-13
Abstract: Halogenated alcohols are prepared by the condensation of aldehydes or ketones and trihalogen methanes in the presence of the complex body formed from potassium hydroxide and an organic solvent which is a member of the group consisting of dialkyl ethers of aliphatic vicinal glycols, aliphatic acetals and aliphatic ketals, the reaction being carried out in the neighbourhood of 0 DEG  C.  Reaction is preferably discontinued when a conversion of about 85 per cent is attained to prevent undue dehalogenation.  The resulting mixture is treated with ice or ice-water to hydrolyse the potassium salt of the halogenated alcohol formed or hydrolysis may be effected with a dilute aqueous acid.  In examples: (1) acetone and chloroform are reacted in the presence of a complex formed by adding powdered potassium hydroxide to acetal at 0 DEG  C., and the product treated with ice water yielding an aqueous layer containing potassium hydroxide and an organic layer comprising trichloro-tertiary butyl alcohol, acetal and unreacted acetone and chloroform which are recovered by distillation; similarly, using the same complex, acetone and bromoform are reacted to yield tri-bromo-tertiary butyl alcohol and methyl ethyl ketone and chloroform to yield trichloro-tertiary amyl alcohol; (2) by the above procedure carried out in the presence of a potassium hydroxide-methylol complex, acetone and chloroform yield tri-chloro-tertiary butyl alcohol, methyl-ethyl ketone and chloroform yield trichloro-tertiary amyl alcohol, cyclohexanone and chloroform yield 1-trichloromethyl cyclohexanol - 1, acetophenone and chloroform yield methyl-phenyl-trichloromethyl carbinol, methyl-isobutyl ketone and chloroform yield methyl-isobutyl-trichloromethyl carbinol, 2-ethyl-hexanol and chloroform yield 1.1.1 - trichloro - 3 - ethyl - heptanol - 2, and isobutyraldehyde and chloroform yield trichloromethyl-isopropyl carbinol; (3) acetone and chloroform are reacted as in (1) using a potassium hydroxide - butyraldehyde - dibutyl acetal complex; (4) cyclohexanone and chloroform are reacted as above, using, however, a complex of potassium hydroxide and acetaldehyde dibutyl acetal.  Other starting materials mentioned are benzaldehyde and ketones generally, including aliphatic and aromatic substituted and cyclic ketones.  In place of the acetals mentioned, other solvents of the types specified may be employed; they contain in their molecule two ether-oxygen atoms separated from each other by not more than two carbon atoms and may be represented as <FORM:0587275/IV/1> where R represents the same or different alkyl radicals and R1 represents hydrogen or the same or different alkyl radicals.  They include the acetals from 2-ethyl hexanol and methyl alcohol and from formaldehyde and propylene glycol; the ketals from methyl-ethyl ketone and ethylene glycol and from acetone and butyl alcohol; and ethylene glycol-ethyl-butyl-ether, ethylene glycol dibutyl-ether and propylene glycol-ethyl-butyl ether.  Specifications 573,527, 578,082, 580,921, 580,922 and 584,607, and German Specification 515,539 are referred to.