2-broMo-4-ethylthiazole synthesis

Yield:89322-56-5 40.04%

Reaction Conditions:

Stage #1: 2-amino-4-ethylthiazolewith tert.-butylnitrite in acetonitrile at 0; for 0.166667 h;
Stage #2: with copper(ll) bromide in acetonitrile at 0; for 0.5 h;

Steps:

67 Synthesis of compound 67.1.

To a solution of compound 67 (0.5g, 3.90mmol, 1.0eq) in acetonitrile (10ml) was added tert-Butyl nitrite (0.5mL, 4.29mmol, 1.1eq) at 0°C and stirred for 10min. Copper (II) bromide (0.608g, 2.73mmol, 0.7eq) was added and reaction mixture was stirred at 0°C for 30min. After completion of reaction, reaction mixture was transferred into water and product was extracted with ethyl acetate. Organic layer was combined, washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure to obtain crude material. This was further purified by column chromatography and compound was eluted in 2.0% ethyl acetate in hexane to obtain pure 67.1. (0.3g, Yield: 40.04%). MS(ES): m/z 191.94 [M+H] ⁺.

References:

WO2020/112937,2020,A1 Location in patent:Paragraph 00754