1,209,140. Selective halogenation of paraffins. LABOFINA S.A. 2 July, 1969 [4 Feb., 1969], No. 33482/69. Heading C2C. A process for the selective halogenation of a paraffin RCH 2 CH 3 to obtain preferentially RCHXCH 2 , (where X is Cl or Br and R is a straight- or branched-chain primary alkyl group) comprises reacting it in the liquid phase with a Co<SP>III</SP> salt, an activator (BF 3 and/or an acid for which K is greater than 5 x 10<SP>-3</SP>) and as halogen donor, Br 2 or a compound ZX, where Z is a radical stabilized by resonance and is not reactive in respect of the paraffin, at - 20‹ to 100‹ C. in absence of O 2 . Specified compounds ZX fall within the formulµ CX 4 , CHX 3 , CH 2 X 2 , CX 3 CO 2 H, CHX 2 CO 2 H, BrCH 2 CO 2 H, Me 2 CBr- CO 2 H, esters of these acids, CCl 3 CN and CHBr 2 CN. Exemplified paraffins are heptane, decane, 2-methylpentane and 2-methylhexane. Specified by-products are alcohols RCHOHCH 3 , their acetates and ketones RCOCH 3 .