2(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl- → 2-(2,2-dimethoxy-1-ethyl)-5-methoxy-1-tetralone N,N-dimethylhydrazone

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Reaction Steps

3.12 g of 5-methoxy-1-tetralone N,N-dimethylhydrazone and 4.15 ml of DMPU were dissolved in 70 ml of absolute THF under argon and cooled to -75°. 10.7 ml of a 1.6M solution of n-butyllithium in hexane were added dropwise. The mixture was stirred at -75° for 1 hour and thereupon treated slowly with 2.0 ml of bromoacetaldehyde dimethyl acetal. The mixture was left to warm to room temperature and stirred for 26 hours. 20 ml of water were added at about 0° and the mixture was extracted three times with ethyl acetate. After drying over sodium sulfate, the mixture was filtered, evaporated and the residue was chromatographed on silica gel with toluene, then with toluene/ethyl acetate 9:1. 1.62 g (37%) of 2-(2,2-dimethoxy-1-ethyl)-5-methoxy-1-tetralone N,N-dimethylhydrazone were obtained as an oil.

Provenance & Evidence