What type of halide is primarily produced using thionyl chloride?

Thionyl chloride (SOCl2) is commonly used in organic chemistry as a reagent to convert alcohols into alkyl halides. The reaction proceeds through a mechanism where the alcohol reacts with thionyl chloride to form an intermediate that subsequently leads to the formation of the alkyl halide.

Thionyl chloride tends to favor the formation of primary alkyl halides because its nucleophilic attack is less hindered compared to secondary or tertiary alcohols. The presence of bulky groups in tertiary and secondary alcohols can hinder the approach of the thionyl chloride, making it less efficient in these cases. Therefore, the reaction is more successful with primary alcohols, resulting in the formation of primary alkyl halides.

Additionally, the reaction with thionyl chloride can also produce byproducts such as sulfur dioxide and hydrogen chloride, which can further confirm the conversion of the alcohol to the desired alkyl halide. This preference aligns with the fact that thionyl chloride typically leads to the formation of primary alkyl halides through its effective, less sterically hindered mechanism.