The disclosed invention relates to a process, comprising: flowing a first reactant feed stream (314) comprising a reactant substrate and a second reactant feed stream (342) comprising an alkylating agent, an acylating agent or a mixture thereof, in a process microchannel (310) in contact with each other to form a product (316) comprising at least one alkylation product, at least one acylation product, or a mixture thereof; transferring heat from the process microchannel to a heat sink (320); and removing the product (316) from the process microchannel.