Sodium Bicarbonate → HCID 178491174, compound

Participants

Reaction Conditions

Reaction Steps

27.64 g of tin chloride dihydrate are added portionwise to a suspension of 10.72 g of 4-nitro-1H-pyrazole-3-carboxylic acid 2,4-dimethoxybenzylamide in 600 ml of absolute ethanol. The reaction medium is stirred for 48 hours at 20° C. The clear brown solution obtained is brought to dryness on a rotary evaporator. The clear brown foam obtained is taken up in 700 ml of a 90/10 by volume a mixture of methylene chloride/methanol. 700 ml of saturated aqueous sodium hydrogen carbonate solution are added to the brown solution obtained. The cream-colored suspension obtained is stirred for 1 hour at room temperature. 30 g of Clarcel Flo are added to the suspension and the mixture is then stirred for 10 minutes at room temperature. The resulting mixture is filtered and the filter cake is washed with twice 250 ml of a 90/10 by volume a mixture of methylene chloride/methanol. The solid is drained by suction and the filtrate is recovered and then transferred into a separating funnel. The chloromethylene phase is separated out by settling and the aqueous phase is then re-extracted with twice 250 ml of dichloromethane. The organic phases are combined and then dried over magnesium sulfate, filtered through paper and then brought to dryness on a rotary evaporator. 8.53 g of 4-amino-1H-pyrazole-3-carboxylic acid 2,4-dimethoxybenzylamide are obtained in the form of a pale pink solid. ([M+H]+): 277). RT: 2.36 min (Method A).

Provenance & Evidence