Pivaloyloxymethyl hydrochloride

Bj Pivaloyloxymethyl D(—)-Ot-aminobenzylpenicillinate. hydrochloride To a solution of pivaloyloxymethyl D(—)-a-azidobenzylpenicillinate (prepared as described above) in ethyl acetate (75 ml) a 0.2 M phosphate buffer (pH 2.2) (75 ml) and 10% palladium on carbon catalyst (4 g) were added, and the mixture was shaken in a hydrogen atmosphere for 2 hours at room temperature. The catalyst was filtered off, washed with ethyl acetate (25 ml) and phosphate buffer (25 ml), and the phases of the filtrate were separated. The aqueous phase was washed with ether, neutralized (pH 6.5 to 7.0) with aqueoussodium bicarbonate, and extracted with ethyl acetate (2 X 75 ml). To the combined extracts, water (75 ml) was added, and the pH adjusted to 25 with 1 N hydrochloric acid. The aqueous layer was separated, the organic phase extracted with water (25 ml), and the combined extracts were washed with ether, and freeze-dried. The desired compound was obtained as a colorless, amorphous powder. 

Pivoxil hydrochloride (miconazole pivaloyloxymethyl chloride) Micomax, Pivaanazolo [4]. 

The pivaloyloxymethyl group can be removed under mildly basic conditions, which makes it highly suitable for the synthesis of sensitive nucleosides. -E 3-Benzyloxymethyl-7-pivaloyloxymethyladenine hydrochloride dissolved in NHj-satd. methanol, and the product isolated after 2 hrs. at 25 3-benzyl-oxymethyladenine. Y 75%. F. e. s. M. Rasmussen and N. J. Leonard, Am. Soc. 89, 5439 (1967) 90, 2488 (1968). 

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