반응 #74596

반응 방정식

sodium hydrogencarbonate

2,4-Dimethoxybenzaldehyde

2-amino-1,3,4-thiadiazole

Sodium tetrahydroborate

→

title compound

수율 73.5%

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

수율 73.5%

용매

xylene

2-methyltetrahydrofuran

water

Methanol

반응 조건

후처리

1. 1
   온도heated to reflux
2. 2
   기타to remove the water
3. 3
   온도the reaction was further cooled to 5° C.
4. 4
   workup.ADDITIONdiluted with 2-methyltetrahydrofuran (2.93 L)
5. 5
   온도maintaining the temperature below 15° C
6. 6
   workup.STIRRINGthe mixture stirred at room temperature overnight
7. 7
   온도heated to 43° C.
8. 8
   workup.DISSOLUTIONdissolution
9. 9
   기타The layers were separated
10. 10
    세척the organic layer washed with water (3 L)
11. 11
    농축before concentrating in vacuo
12. 12
    workup.STIRRINGhomogenised
13. 13
    여과filtered
14. 14
    세척washed with tert-butylmethyl ether
15. 15
    기타dried

실험 절차

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.

출처