This study focuses on economic preparation of a phosphinated dietheramine for soluble polyetherimides. For this purpose, a phosphinated dietheramine, 1,1-bis(4-(4-aminophenoxy)phenyl)-1-(6-oxido-6H-dibenz < c,e > < 1,2 > oxaphosphorin-6-yl)ethane (3), was prepared from the nucleophilic substitution of a alkaline-stable biphenol,1,1-bis(4-hydroxyphenyl)-1-(6-oxido-6H -dibenz < c,e > < 1,2 > oxaphosphorin-6-yl)ethane (1), with 4-chloronitrobenzene using inexpensive potassium carbonate as catalyst, followed by catalytic hydrogenation. Light color, and foldable polyetherimides (PEls) with good thermal stability, improved organo-solubility, and good flame retardancy were synthesized from the condensation of (3) with various aromatic dianhydrides in DMAc, followed by thermal imidization. Properties of the resulting PEls were evaluated and compared with those of PEls based on a commercially available dietheramine, 2,2-bis (4-(4-aminophenoxy)phenyl) propane (BAPP). The T(g)s of the resulting PEls range from 271 degrees C to 314 degrees C by dynamic mechanical analysis. The degradation temperatures (T-d 5%) range from 453 to 467 degrees C in N-2 atmosphere, and 435-451 degrees C in air atmosphere. The resulting PEls also show good flame retardancy. (C) 2011 Elsevier Ltd. All rights reserved.