Synthesis of 3-(Organyloxymethyl)tetrahydro-1,3-oxazines

Abstract

3-(Organyloxymethyl)tetrahydro-1,3-oxazines were synthesized by the condensation–heterocycliza­tion of 3-aminopropan-1-ol, formaldehyde, and various hydroxyl-containing compounds. 3,3′-methylenebis­(tetra­hydro-2H-1,3-oxazine) was also formed as byproduct in ~10% yield. The yield of the title compounds increased in parallel with the length of the hydrocarbon chain in the initial alcohol. Furthermore, the yields of the target products obtained from unbranched alcohols were higher than in the reactions with their branched isomers. The product structure was determined by ¹³C NMR spectroscopy. The effect of the organyloxymethyl substituent on the ¹³C chemical shifts of the endocyclic carbons in comparison to unsubstituted tetrahydro-1,3-oxazine and 3-methyltetrahydro-1,3-oxazine was studied.