t-Butyl acetate as a t-butyl cation equivalent: O-Alkylation of N-Hydroxyphthalimide; t-butoxyphthalimideSyntheticPage 145 (2001)
Submitted 28th Aug 2001, published 28th Aug 2001
A contribution from the Walton Group, St. Andrews
1,4-dioxane (300 ml),
t-butyl acetate (75 ml; 0.56 mol),
N-hydroxyphthalimide (8.15 g; 0.05 mol),
72% perchloric acid (0.5 ml).
The reagents are mixed together (in order listed), and stirred in a stoppered flask for 24 hours at room temperature. Saturated aqueous sodium bicarbonate solution is added until there is no more effervescence (~200 ml). The organic layer is separated, and concentrated. The crystals are dissolved in ether, dried and concentrated, then recrystallised (40/60 Petrol). Yield: 8.81 g; 80%.
The reference that the procedure was taken from (see below) was in Russian, and our translation indicated that the dioxane layer should be extracted with DCM, but the solvents were miscible, so the method described was used. A first attempt, in which the mixture turned blood-red, failed for unknown reasons and the successful attempt seemingly followed the same procedure.
The technique was used because the usual way to prepare N-alkoxyphthalimides, Mitsonobu condensation ([SyntheticPage 122] ), failed.
m.p. 110.5-113 oC. (lit 110-111 oC; Chimiak and Kolasa)1H nmr (300 MHz, CDCl3) 1.43 (9H,s), 7.65-7.85 (4H, ArH)
A. J. McCarroll and J. C. Walton, J. Chem. Soc. Perkin Trans. 2, 2000, 1868.
A. Chimiak, T. Kolasa. Rocz. Chem., 1974, 48, 139.
t-Butyl acetate is reported to be a good general t-butylating agent in the presence of a strong acid. E. Taschner, Cz. Wasielewski, J. F. Biernat, Ann., 1961, 646, 119.
This page has been viewed approximately 120 times since records began.
Get CDX file (Choose "Open this file from its current location" TWICE)
SyntheticPagesTM are for use
exclusively by those with training and experience in synthetic chemistry. While contributors
are asked to identify hazards and to use methods designed to reduce risk, no formal hazard
or risk assessments are included, and these procedures must be conducted at one's own risk.
SyntheticPages, its editors, owners and associates do not warrant or guarantee the safety of
individuals using these procedures and hereby disclaim any liability for any injuries or damages
claimed to have resulted from or related in any way to the procedures herein. Copyright ©2004 Synthetic Pages
Comment on this page!
Registered users may add comments to other pages. If you have already registered, please
log in, otherwise you may
Back to List