A Scalable Procedure for the Synthesis of BAMO

Abstract 3,3‐bis(azidomethyl)oxetane (BAMO) homopolymer is used as binder in the formulation of some solid propellants. Herein, the synthesis of BAMO by two methods (three or two steps) has been reinvestigated following which, using pentaerythritol as a starting material, chlorination, oxetane ring formation and finally azidation of the produced oxetane have been performed. Following three steps method, the yield of the principal product of the first step (pentaerythritol trichloride) was increased by optimizing the reaction temperature, reaction time and proportional amount of the starting materials. The products of the first step were used in the second step without any further purification, using different amount of base and varying reaction time, affording 3,3‐bis(chloromethyl)oxethane (BCMO) as the principal product with increased yield. The reaction mixture of the second step was lead to the third step where, using excess amount of base and sodium azide, all the reactants coming from the first and second step (BCMO and other side products as pentaerythritol tetrachloride and 3‐chloromethyl‐3‐hydroxymethyl oxetane) were transformed to BAMO. Overall yield via three steps following optimized conditions was 60 % based on pentaerythritol. All products in each step were recognized by GC and GC‐MASS and BCMO and BAMO were also characterized by IR, 13C‐NMR and 1H‐NMR. In another attempt and following a two steps method, the products of the first step (chlorination of pentaerythritol) were used without any further purification in the second step where simultaneous usage of base and sodium azide (and conjoint formation of oxetane ring and its azidation) has afforded BAMO with an overall yield of 75 %.