Choreographies present how parties collaborate to achieve an agreed business objective. When companies are bought, their processes have to be in-sourced. Thereby, their part in a choreography has to be merged with the part of their acquiring business partner. Merging patterns may be applied to merge reoccurring activity combinations, such as send/receive. It has to be proven that each merge patterns keeps the relations of the original activities of the choreography. As a first step, we show by an example how the relations between activities may be expressed using the Allen calculus. We show for merging a synchronous message exchange, which relations have to be considered for validating an implementation of that merge.