Electrochemical synthesis of 1,3-dimethyl-4-amino-5-formyluracyl in the presence of ammonium chloride

Abstract

The synthesis of 1,3-dimethyl-4-amino-5-formyluracyl, an intermediate of theophylline synthesis, was studied in an ammonium chloride medium using the electroreduction of 1,3-dimethyl-4-amino-5-nitrosouracyl to a diamino derivative with its further formylation. The electrolysis and formylation conditions were optimized. The reduction of 1,3-dimethyl-4-amino-5-nitrosouracyl was performed under the following conditions: its concentration was 12.0–13.5 %, the cathode was a Kh18N10T stainless steel gauze, the electrolysis was performed in the presence of ammonium chloride, the current density was 7.5–8.0 A/dm², the electrolysis temperature was 40–45°C, and the formylation temperature was 71–72°C. The substance yield of overall formylaminouracyl was 81.2–83.3% and the current efficiency was 62.0–64.5%. The developed process of 1,3-dymethyl-4-amino-5-formyluracyl synthesis was evaluated at a scaled-up laboratory setup with a filter-press cell.