Synthesis of 2-substituted morpholines from dihydroxyalkylsulfamates

Abstract

2-Substituted morpholines and hexahydro-l,4-oxazepines were prepared by cyclodehydration of potassium dihydroxyalkylsulfamates in concentrated sulfuric acid.

Sulfamic Acid and Its N- and O-Substituted Derivatives

“…N-Substituted aminomethyl-1,4-dioxane 30 and 2,5-bis(aminomethyl)-1,4-dioxane 31 have been prepared in generally good yields by cyclization of the corresponding potassium N-[3-(2-chloroethoxy)-2hydroxypropyl]sulfamates 32. 135 Cyclodehydration of potassium dihydroxyalkylsulfamates in concentrated H 2 SO 4 gave 2-substituted morpholines and 1,4oxazepines, 136 nitration of 2-hydroxyalkylsulfamates, and subsequent conversion of the nitroamines formed into ammonium salts followed by cyclization in methanolic alkali gave 4,5dihydro-1,2,3-oxadiazole 2-oxides 33 137 in moderate yield and reaction of 2-hydroxyethylsulfamate and 2-substituted acetaldehydes gave rise to N-nitrooxazolidines 34. 138 Dinitramidic acid and its ammonium salt have been prepared by nitration of ammonium sulfamate with fuming HNO 3 using solid acid catalysts such as montmorillonite clay.…”

“…Cyclodehydration of potassium dihydroxyalkylsulfamates in concentrated H 2 SO 4 gave 2-substituted morpholines and 1,4-oxazepines, nitration of 2-hydroxyalkylsulfamates, and subsequent conversion of the nitroamines formed into ammonium salts followed by cyclization in methanolic alkali gave 4,5-dihydro-1,2,3-oxadiazole 2-oxides 33 in moderate yield and reaction of 2-hydroxyethylsulfamate and 2-substituted acetaldehydes gave rise to N -nitrooxazolidines 34 …”