Hypophosphoric acid → Methyl 4-Methylbenzothiazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

15 g of methyl 2-amino-4-methylbenzothiazole-5-carboxylate (0.07 mol) were initially charged in 450 ml of phosphoric acid, and the mixture was cooled to −8° C. 27.9 g of NaNO2 (0.4 mol) in 30 ml of water were then added dropwise such that the temperature did not exceed −4° C. The diazonium salt was then added dropwise, at 5-10° C., to 169 ml of hypophosphoric acid, and the mixture was stirred at 20° C. overnight. The reaction solution was then neutralized and extracted exhaustively with ethyl acetate. The organic phases Age were washed and dried and the solvent was then removed.

Provenance & Evidence