Water → HCID 70469116, compound

Participants

Reaction Steps

2.93 g (10 millimole) of trans-4-diazoacetyl-1-(2,4-dimethoxy-benzyl)-3-ethyl-2-azetidinone-which may contain some methyl-trans-1-(2,4-dimethoxy-benzyl)-3-ethyl-4-oxo-2-azetidine-carboxylate too--are dissolved in 100 ml of peroxide-free tetrahydrofuran and to the solution 50 ml of water are added. The solution is irradiated with a high pressure mercury vapor lamp (HPK) under argon in a pyrex apparatus equipped with a submersed lamp for about 4 hours (until the diazoacetyl derivative is converted). From the solution the tetrahydrofuran is evaporated in vacuo, the residue is diluted with water to 150 ml and made alkaline by adding 4 ml of a 10% aqueous sodium hydroxide solution. The alkaline solution is extracted three times with 30 ml of dichloromethane each and the aqueous phase is acidified with concentrated hydrochloride acid to pH 2. The acidic solution is extracted three times with 30 ml of dichloro methane each. The organic phase is dried over anhydrous magnesium sulfate, filtered and the filtrate is evaporated to dryness. On rubbing with ether the residue becomes crystalline. Thus 1.44 g of the desired compound are obtained, yield: 47.1%. M.p.: 131° C.

Provenance & Evidence