The Boston Marathon explosions were on the minds of officials in Manhattan yesterday as a would-be city synagogue bomber was sentenced to five years’ prison.

Mohamed Mamdouh, 22, a naturalized citizen from Morocco, had pleaded guilty in a closed-court proceeding last year to conspiracy and weapons possession as crimes of terror.

His co-defendant, Algerian citizen Ahmed Ferhani, got a 10-year sentence last month as the scheme’s mastermind.

The two had been taped during an eight-month NYPD undercover operation plotting to throw a grenade into an unspecified synagogue and to wire multiple bombs to a single detonator to blow up several synagogues simultaneously.

DA Cyrus Vance Jr. said the sentencing “marks the successful conclusion of New York’s first state-level terror prosecution.”