Ethanol → (-)-6-[(4-chlorophenyl)-hydrazinomethyl]-1-methyl-1H-benzotriazole (R)-alpha-hydroxybenzeneacetate

Participants

Reaction Conditions

Reaction Steps

To a mixture of 200 g of intermediate 2-a and 479 ml of ethanol at 23° C. was added a solution of 23.94 g of sodium hydroxide in 180 ml of water. After stirring for 10 min. there were added 50.2 g of (-)-(R) α-hydroxybenzeneacetic acid. The whole was stirred for 30 min. at 60° C. and the product was crystallized by adding some product crystals obtained in a previous low-scale set-up. Then the whole was stirred for 2 hours at 50° C. and overnight at room temperature. The reaction mixture was cooled (temp. 14° C.) and stirred for 1 hour. The product was filtered off, washed with ethanol and dried in vacuo, yielding 118.8 g (87%) of (-)-6-[(4-chlorophenyl)-hydrazinomethyl]-1-methyl-1H-benzotriazole (R)-α-hydroxybenzeneacetate (1:1) monohydrate (interm. 3-a); diastereomeric excess: 92.6%.

Provenance & Evidence