反応 #74596

反応方程式

sodium hydrogencarbonate

2,4-Dimethoxybenzaldehyde

2-amino-1,3,4-thiadiazole

Sodium tetrahydroborate

→

title compound

収率 73.5%

N-(2,4-Dimethoxybenzyl)-1,3,4-thiadiazol-2-amine

収率 73.5%

溶媒

xylene

2-methyltetrahydrofuran

water

Methanol

反応条件

後処理

1. 1
   温度heated to reflux
2. 2
   その他to remove the water
3. 3
   温度the reaction was further cooled to 5° C.
4. 4
   workup.ADDITIONdiluted with 2-methyltetrahydrofuran (2.93 L)
5. 5
   温度maintaining the temperature below 15° C
6. 6
   workup.STIRRINGthe mixture stirred at room temperature overnight
7. 7
   温度heated to 43° C.
8. 8
   workup.DISSOLUTIONdissolution
9. 9
   その他The layers were separated
10. 10
    洗浄the organic layer washed with water (3 L)
11. 11
    濃縮before concentrating in vacuo
12. 12
    workup.STIRRINGhomogenised
13. 13
    ろ過filtered
14. 14
    洗浄washed with tert-butylmethyl ether
15. 15
    その他dried

実験手順

2,4-Dimethoxybenzaldehyde (771.37 g, 4.64 moles) was added to a suspension of 2-amino-1,3,4-thiadiazole (391.2 g, 3.87 moles) in xylene (5.87 L) and heated to reflux. Dean-Stark apparatus was used to remove the water and the reaction was stirred overnight. After cooling to room temperature, the reaction was further cooled to 5° C. and diluted with 2-methyltetrahydrofuran (2.93 L). Sodium tetrahydroborate (73.17 g, 1.93 moles) was added as a single portion. Methanol (782.8 mL) was then added slowly over 30 minutes, maintaining the temperature below 15° C. After a further 30 minutes water (1 L) was added followed by saturated aqueous sodium hydrogencarbonate solution (1 L) and the mixture stirred at room temperature overnight. The biphasic mixture was diluted with 2-methyltetrahydrofuran and heated to 43° C. to aid dissolution. The layers were separated and the organic layer washed with water (3 L) before concentrating in vacuo. The resulting solid was slurried in heptanes (2.5 L), homogenised, filtered, washed with tert-butylmethyl ether and dried to afford 715 g of the title compound.

出典