Decomposition of 2‐propenoyl azide (1c) with nitrogen, oxygen, and sulfur nucleophiles affords the azido displacement products. Ring closure of some of these products produces the heterocyclic systems pyrimidone (3), oxadiazine (6), oxadiazole (8), benzimidazole (10), benzothiazole (12), and benzoxazinone (14). The larvicidal activity of some of these products against Culex pipiens was evaluated.