Ammonium Hydroxide → 2-Amino-5-Nitrothiazole

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 3.5 g of N,N-dimethyl-2-nitroetheneamine in 25 ml of acetic acid cooled to 17° C. was added 4.8 g bromine at such a rate the reaction temperature did not exceed 25° C. During bromination an orange solid was formed. After stirring the resulting slurry for 10 minutes, 3.0 g thiourea was added and the reaction mixture exothermed to 32° C. A yellow solid formed. The mixture was stirred for 1 hour and then was diluted with 25 ml of water. This mixture and an approximately equal volume of 29% ammonium hydroxide were added simultaneously to 25 ml of acetic acid at such rates that the pH remained between 4 and 5 and the temperature did not exceed 30° C. After all of the reaction mixture had been added the pH was adjusted to 7 with 29% ammonium hydroxide. The product was then filtered off, washed with water and dried to give 2.7 g (62% yield, 92.9% assay) of 2-amino-5-nitrothiazole.

Provenance & Evidence