If the seller refuses to sell after signing a valid purchase contract and the buyer wants the property instead of monetary damages, the buyer will most likely sue for:

Specific performance

Explanation:When the seller of the property no longer want to abide by the things written in the contract , eventhough they are capable of performing those promises that were stipulated in the contract but simple refuse to do so a buyer has the legal right to sue for specific performance.

Specific performance refers to all those performance that are stipulated in the contract which make the contract valid if they are all met.