A paragraph break is appropriate here since a new character is introduced (so Revised Standard Version, Good News Bible).

Now a certain Alcimus, who had formerly been high priest: A certain Alcimus is simply a way of introducing this character for the first time in the narrative. Good News Bible has “There was a man by the name of Alcimus,” and New English Bible says “There was a man called Alcimus.” The Greek verb form used in the clause who had formerly been high priest can also be interpreted to mean that he had earlier been appointed High Priest and still was. In verse 7 Alcimus seems to say that he is no longer High Priest, but another interpretation of what he said is possible (see the comments there). In verse 4 Alcimus seems to appear before the new king to seek confirmation of an office he already has. This is Doran’s position (with which Goldstein partially agrees), and we believe he is right. If Alcimus were not the legally recognized High Priest, it would be hard to understand what he was doing in Antioch and why the king asked for his advice (verse 5). He certainly does not seem to have been relieved of office by any royal authority. We will assume here that Alcimus actually was the High Priest at that time. So we may translate the beginning of this verse as “At this time a man named Alcimus held the office of High Priest [in Jerusalem].”

But had wilfully defiled himself in the times of separation: Defiled himself does not necessarily refer to any specific incident; it seems to refer to Alcimus’ participation in the campaign to Hellenize Jewish society. The Greek word rendered defiled himself does not necessarily refer to ritual defilement, but can mean “disgrace,” which is the sense we prefer here (see the model below). The times of separation is a puzzling phrase. There is first of all a textual problem. Separation translates the Greek noun ameixia, basically signifying an unwillingness to mix. Some manuscripts use the Greek noun epimeixia, basically meaning a willingness to mix. The two terms can refer to “war” and “peace,” respectively. Goldstein argues at length for the reading “the time of peace,” as opposed to “the time of war/persecution.” The word ameixia is used in verse 38 to refer to the time of “no mingling with the Gentiles,” and the context there is definitely a time of persecution, presumably under Antiochus~IV. Goldstein builds his case on the contrast of circumstances in verses 3 and 38. In our judgment it is safest to follow the usual text here, which has ameixia, and interpret the reference to be to the time of Antiochus~IV, when pious Jews tried to keep themselves away from the Gentiles. This was the time of the Maccabean “revolt,” which is the word chosen by Good News Bible to translate ameixia (also Revised English Bible, New American Bible, Traduction œcuménique de la Bible, Abel; similarly New English Bible, New Jerusalem Bible). An alternative model for this whole clause is “but during the rebellion [or, when Judas and his men rebelled against the Gentiles] he had disgraced his position.”

Realized that there was no way for him to be safe or to have access again to the holy altar: Alcimus realized that Jewish feeling was so strong against him that he could never serve at the holy altar in front of the Temple, and that he was actually in physical danger from Jews who thought he had betrayed their religion. As in Good News Bible, we suggest joining this last half of the verse to the first clause of the next verse rather than to the preceding material (see the model in the discussion on the next verse).

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.