In the third volume of Craig Keener’s massive Acts commentary, he has a long excursus on the relationship between Acts and the Pastorals (pp. 3023-3026). Probably the most significant part of the excursus is the thorough chart listing the itineraries (people, places and events) of the Pastorals, Acts and the earlier Pauline letters side by side. This is very helpful. In the end, Keener is convinced of a second imprisonment for Paul which is described in 2 Timothy- the traditional explanation.