Reactions and Mechanisms

Question

1. Write a chemical equation for the reaction of 1-butanol with each of the following:

(a) Sodium amide (NaNH2)

(b) Hydrogen bromide, heat

(c) Sodium bromide, sulfuric acid, heat

(d) Phosphorus tribromide

(e) Thionyl chloride

(f) Methanesulfonyl chloride, pyridine

Please show step by step for each reaction.

Answer 1

(d) Phosphorus tribromide

Primary alcohols react readily with phosphorus halides via an SN2 type of mechanism which causes inversion at the center that it is attacking. In your case 1- butanol is a primary alcohol but does not have a chiral center. when 1-butanol reacts with PBr3, the alcohol is replaced by a Bromide and you obtain 1-bromobutane.

Answer 2

a) 1-Butanol + NaNH₂ --> 1-Butanamine + NaOH (Elimination SN2).

Explanation:

1-Butanol reacting with Sodium Amine (NaNH2) would result in a substitution reaction. The ammonia group (-NH₂) acts as a nucleophile, replacing the -OH group in 1-butanol. After the reaction, the products would be butanamine (C₄H₉NH₂) and sodium hydroxide (NaOH). The reaction can be shown as follows:

1-Butanol (C₄H₉OH) + Sodium Amine (NaNH₂) -> 1-Butanamine (C₄H₉NH₂) + Sodium Hydroxide (NaOH)

Remember, these are general reactions and actual laboratory conditions may affect the presence and amounts of the products.

Note: You have the opposite configuration for the product: if the reactant is the (R)-2-butanol the product will be the (S)-2-butanamine. Here, the reactant has no enantiomer so it's not to be considered.

b) c) d) e) f) Let me know if you want these answers.