1,4-Dioxane → HCID 12817546, compound

Participants

Reaction Steps

A mixture of (1S,3S,5R,6R) 6-(4-nitrobenzyloxycarbonyl)amino-2,2-dimethylpenam-3-carboxylic acid-1-oxide p-nitrobenzyl ester (8.19 g, 15.0 mmol), trichloroacetyl isocyanate (5.0 ml, 7.9 g, 42 mmol) and dioxane (75 ml) was refluxed under nitrogen for 3.5 hours and concentrated in vacuo to a light brown oil. The oil was stirred with warm methanol (150 ml) for 0.5 hour and the solution was decanted from a small amount of dark residue. The methanol solution was adjusted to pH 7.4 with 5% sodium bicarbonate and held at pH 7.4-7.5 with 3% sulfuric acid during a 2.0 hour stirring period. The mixture was then distributed between methylene chloride (250 ml) and water (100 ml). The organic layer was washed with water (100 ml), combined with a CH2Cl2 back-extract (100 ml), dried (4A molecular sieve), polish filtered, and concentrated in vacuo to a light brown oil.

Provenance & Evidence