Reference of 54-20-6 ,Some common heterocyclic compound, 54-20-6, molecular formula is C5H3F3N2O2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.
To a jacket reactor (500 mL) is added 5-trifluoromethyluracil (5-TFU, 40 g, ~ 70 % assay, ~ 0.16 mol, 1 .0 eq.), H3PO4 (2.4 g; 0.02 mol, 0.13 eq.) and POCI3 (128 g; 0.83 mol, 5.2 eq.) (a white suspension is formed). DIPEA (35 g, 0.27 mol, 1 .69 eq.) is added to the suspension dropwise in about 10 min and then the reaction mixture is heated to 1 10-120 C (clear solution). The reaction is monitored with HPLC until ratio 5-TFU:5-TFP < 5:95 (reaction normally finished in 7-8 h; if reaction is not complete, additional POCI3 (5 g, 0.032 mol, 0.2 eq) and DIPEA (1 .3 g, 0.01 mol, 0.06 eq) are charged and stirred for another 1 -2 h). The reaction is then cooled to rt and n-butyl acetate (80 mL) is added to the reaction mixture. About 60 mL of distillate (POCI3 and some n-butyl acetate) is collected at 63-65 C/450-500 mbar. The resulting dark solution is slowly added to a mixture of cone. HCI (165 g, 27 weight %, 1 .23 mol, 7.7 eq.) and methyl tertiary butyl ether (MTBE, 120 mL) while the temperature is maintained below 20 C. The organic phase is separated and the aqueous phase is extracted with MTBE (2 x 120 mL). The organic phase is gathered, washed with water until the pH value reaches ca. 5-6. MTBE is removed under reduced pressure (~ 42 C/200 mbar), the final product is purified through distillation (87-89 C/55 mbar) to afford 5-TFP as colorless oil (25.3 g, yield 72.9 %; purity 98 %). 2,4-dichloro-5-trifluoromethylpyrimidine (5-TFP) Colorless to light yellow oil 1H NMR (CD3COCD3): delta 8.8 (s, 1 H), 19F NMR (CD3COCD3): delta -63.7 ESI MS (m/z) 216 [M-1 ]"
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route,54-20-6, its application will become more common.
Reference:
Patent; BOEHRINGER INGELHEIM INTERNATIONAL GMBH; BOEHRINGER INGELHEIM INTERNATIONAL TRADING (SHANGHAI) CO., LTD.; LIU, Li; AKALAY, Deniz; DONG, Weitong; FENG, Jianqing; HEMP, Christian Wolfgang; LU, Jun; XIE, Le; YANG, Jinsong; WO2014/76085; (2014); A1;,
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