反応 #60767

反応方程式

ammonium hydroxide

4-Amino-3-(4-nitrophenyl)thieno[2,3-d]pyrimidine

HCl

tin

→

4-Amino-3-(4-aminophenyl)thieno[2,3-d]pyrimidine

溶媒

ethyl acetate

反応条件

後処理

1. 1
   その他The system was placed in an ice bath
2. 2
   その他At this point, extensive precipitation
3. 3
   ろ過Precipitate (A) was collected by filtration
4. 4
   workup.ADDITIONthe clear solution was treated with 1 L methylene chloride
5. 5
   抽出The aqueous layer was then back-extracted with 3×200 mL methylene chloride
6. 6
   乾燥dried over anhydrous sodium sulfate
7. 7
   ろ過filtered
8. 8
   workup.ADDITIONPrecipitate (A), consisting of a mixture of tin salts and product
9. 9
   抽出was extracted with boiling methanol until washings
10. 10
    ろ過filtered
11. 11
    濃縮concentrated to dryness
12. 12
    その他dried overnight
13. 13
    その他nearly quantitative yield), which was recrystallized from methanol

実験手順

4-Amino-3-(4-nitrophenyl)thieno[2,3-d]pyrimidine (11.6 g; 272 g/mole; 42.6 mmoles) was treated with 500 mL HCl 6N and 15 g elemental tin at room temperature. After 15 minutes the reaction was complete by TLC (product has Rf=0.50 in 100% ethyl acetate). The system was placed in an ice bath and treated with concentrated ammonium hydroxide to pH 10 (˜300 mL). At this point, extensive precipitation was observed. Precipitate (A) was collected by filtration and reserved, and the clear solution was treated with 1 L methylene chloride. The aqueous layer was then back-extracted with 3×200 mL methylene chloride. The organic layers were combined, dried over anhydrous sodium sulfate, and filtered. Precipitate (A), consisting of a mixture of tin salts and product, was extracted with boiling methanol until washings showed no more product by TLC. The resulting solution was combined with the previously reserved organic layers, filtered, concentrated to dryness and dried overnight, generating desired product 4-Amino-3-(4-aminophenyl)thieno[2,3-d]pyrimidine (242 g/mole; nearly quantitative yield), which was recrystallized from methanol.

出典