Ethyl 4-chloroacetoacetate → HCID 13105850, 화합물

HRID 326149

반응식

HRID 326149 반응식
Cl.[NH2:2][C:3]1[S:4][C:5]([Cl:8])=[CH:6][N:7]=1.C([O:11][C:12](=O)[CH2:13][C:14]([CH2:16][Cl:17])=O)C>>[Cl:8][C:5]1[S:4][C:3]2=[N:2][C:14]([CH2:16][Cl:17])=[CH:13][C:12](=[O:11])[N:7]2[CH:6]=1

참가 물질

3

반응물 2

HCID 69484Ethyl 4-chloroacetoacetateHCID 1487432-Amino-5-chlorothiazole hydrochloride

생성물 1

HCID 13105850HCID 13105850, 화합물

반응 조건

온도
110 °C

실험 절차

2-amino-5-chloro-thiazole hydrochloride (8 g) was reacted with ethyl-4-chloroacetoacetate (15.8 g) in polyphosphoric acid (40 g) under stirring at 110° C. for 1 hour. After cooling, dilution with water and neutralization with 35% NaOH, the precipitate was filtered and washed with water. Crystallization from isopropyl ether gave 2-chloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-one, m.p. 123°-125° C. (7.45 g), which was reacted with triphenylphosphine (9.42 g) in acetonitrile (100 ml) under stirring at reflux temperature for 10 hours. After cooling the precipitate was filtered and washed with acetonitrile to give (2-chloro-5H-thiazolo[3,2-a]pyrimidine-5-one-7-yl)-methyl-triphenylphosphonium chloride, m.p. 300°-310° C. dec. (10 g) which was suspended in dimethylsulfoxide (40 ml) and treated with potassium tert-butoxide (2.48 g) dissolved in dimethylsulfoxide (40 ml) at room temperature under stirring for 10 minutes. To the solution of the ylide so obtained 5 -formyl-2-methyl-thiazole (3.1 g) dissolved in dimethylsulfoxide (20 ml) was added and the reaction mixture was kept under stirring at room temperature for 15 minutes: after dilution with ice water and neutralization with NaH2PO4 the precipitate was filtered and crystallized from CH2Cl2 -methanol to give 3.4 g of 2-chloro-7-trans-[2-(2-methyl-5-thiazolyl)-ethenyl]-5H-thiazolo[3,2-a]pyrimidine-5-one, m.p. 224°-226° C., NMR (CDCl3) δ ppm: 2.97 (s) (3H, --CH3), 6.61 (s) (1H, C-6 proton), 6.78 (d) (1H, β-ethenyl proton), 7.82 (d) (1H, α-ethenyl proton), 7.88 (s) (1H, C-3 proton), 8.02 (s) (1H, C-4 thiazolyl proton); JHαHβ =16 Hz.

후처리

  1. temperatureAfter cooling
  2. filtrationdilution with water and neutralization with 35% NaOH, the precipitate was filtered
  3. washwashed with water
  4. customCrystallization from isopropyl ether

출처 및 근거

ORD 기록
ord-41929ebff56a4f98abfa5063d16189cf
출처 데이터셋
uspto-grants-1984_04
특허 번호
US04444773

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