반응 #367926

반응 방정식

sodium carbonate

hypophosphorous acid

charcoal

2-guanidino-4-(2-amino- 4-imidazoyl)thiazole dihydrochloride

sodium nitrate

sulfuric acid

→

2-guanidino-4-(4-imidazoyl)thiazole

수율 5.0%

용매

methanol

water

water

water

반응 조건

후처리

1. 1
   온도was cooled to -10°
2. 2
   workup.STIRRINGstirring
3. 3
   workup.STIRRINGThe reaction was stirred at 50° for 2 hours
4. 4
   workup.WAITat room temperature for 16 hours
5. 5
   추출extracted three times with 150 ml portions of ethyl acetate
6. 6
   건조The combined ethyl acetate extracts were dried over sodium sulfate
7. 7
   여과filtered
8. 8
   기타evaporated
9. 9
   기타leaving a solid
10. 10
    농축concentrated to a small volume
11. 11
    기타The resulting solid was collected
12. 12
    기타dried

실험 절차

A mixture of 42 ml of concentrated sulfuric acid and 21 ml of water was cooled to -10° and 1.56 g (22.7 mmol) of sodium nitrate was added. Afrer stirring at -5° for ten minutes, 8.1 ml (78 mmol) of cold 50% hypophosphorous acid was added and stirring was continued for another 10 minutes at -5°. A solution of 2.5 g (8.4 mmol) of 2-guanidino-4-(2-amino- 4-imidazoyl)thiazole dihydrochloride in 100 ml of water was added dropwise over 0.5 hour. The reaction was stirred at 50° for 2 hours, then at room temperature for 16 hours. The reaction mixture was diluted with 500 ml of water, made basic with solid sodium carbonate and extracted three times with 150 ml portions of ethyl acetate. The combined ethyl acetate extracts were dried over sodium sulfate, filtered, and evaporated leaving a solid. This solid was taken up into boiling methanol, decolorized with charcoal, and concentrated to a small volume. The resulting solid was collected and dried, thereby affording 90 mg (5%) of 2-guanidino-4-(4-imidazoyl)thiazole identical to the material of Example 31 by thin layer chromatography and high resolution mass spectrometry.

출처