Robert Frederick Brookes

Rearrangements and cyclization of ω-alkoxyalkyl- and ω-phenoxyalkyl-carbamoyl chlorides

ω-Alkoxyalkyl- and ω-phenoxyalkyl-carbamoyl chlorides (R1O·[CH2]n·NR2·COCl)(I) rearrange to give, respectively, alkyl or phenyl N-(ω-chloroalkyl)carbamates (II). The rearrangement occurs with the greatest facility when n= 2 or 3. When the carbamates (II)(alkyl but not phenyl) are heated, ring closure readily takes place when n= 2 or 3 to give, respectively, 2-oxazolidones (III) or tetrahydro-1,3-oxazin-2-ones (IV). An analogous rearrangement occurs with 2-ethoxyethyl chloroformate, giving 2-chloroethyl ethyl carbonate.