(2-oxo-2-phenylmethoxyethyl) 4-oxopentanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.2 g of p-methoxyphenylhydrazine were suspended in 25 ml of glacial acetic acid and 90 ml of water and 10 g of benzyl levulinoyloxyacetate were slowly added at room temperature while stirring. After stirring for 1 hour, the mixture was extracted by shaking with toluene, the toluene solution was washed neutral with water, dried and concentrated. 15.1 g of benzyl levulinoyloxyacetate (p-methoxyphenyl)-hydrazone were obtained as a brownish oil, which was not purified but was dissolved in 25 ml of absolute pyridine, and then 100 ml of ether were added and mixed with a solution of 8.7 g of p-chlorobenzoyl chloride in 50 ml of ether at 0°C with the introduction of nitrogen. After boiling for 2 hours under nitrogen, the solution was cooled, washed neutral with water, dried and concentrated by evaporation. 19 g (crude yield) of N(2) -(p-chlorobenzoyl)-N(2) -(p-methoxyphenyl)-hydrazone of benzyl levulinoyloxyacetate were obtained. This product was further treated without purification, by taking it up in 75 ml of glacial acetic acid and heating for 5 hours at 80°C. After evaporating off the glacial acetic acid under vacuum, the further treatment was carried out as described in Example 1. The yield of [1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indoleacetoxy]-benzyl acetate amounted to 11% of the theoretical, based on the total amount of hydrazine. After stirring for 1 hour the mixture was extracted by shaking with toluene the toluene solution was washed neutral with water dried concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5 g (0.016 mol) of N(1) -(p-methoxyphenyl)-p-chlorobenzhydrazide hydrochloride and 4.75 g (0.018 mol) of benzyl levulinoyloxyacetate were heated in 25ml of glacial acetic acid for 3 hours at 80°C. The solvent was then evaporated off under vacuum, the residue was taken up in chloroform and the solution was washed neutral by shaking with sodium bicarbonate solution and thereafter with water. After drying the chloroform solution, this was subjected to chromatography on aluminium oxide, the eluate was concentrated by evaporation and the viscous oil remaining as residue was crystallised by adding ether. The compound melted at 94°-95°C. The yield was 4.1 g which corresponds to 50.7% of the theoretical yield. The solvent was then evaporated off under vacuum the solution was washed neutral After drying the chloroform solution the eluate was concentrated by evaporation was crystallised by adding ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: condensing 4-methoxyphenylhydrazine or its salts with benzyl levulinoyloxyacetate according to Fischer to form (5-methoxy-2-methyl-3-indoleacetoxy)-benzyl acetate, subsequently acylating the alkali salt thereof with p-chlorobenzoyl chloride to form [1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indole-acetoxy]-benzyl acetate and then catalytically dehydrogenating the benzyl group (see reaction scheme A),