Réaction #50939

Équation de réaction

HCl

2-aminothiophenol

diethyl oxalate

water

→

ethyl 2-benzothiazolecarboxylate

Rendement 36.2%

Solvants

EtOH

Conditions de réaction

Traitement

1. 1
   Températureat reflux for 4 hr
2. 2
   workup.ADDITIONpoured into a solution
3. 3
   workup.DISSOLUTIONthe oil dissolved
4. 4
   Autrea solid formed
5. 5
   TempératureThe solution is cooled in an ice bath
6. 6
   Filtrationthe solid is collected by vacuum filtration
7. 7
   Lavagethe solids are washed with a solution
8. 8
   Autreto afford a dark solid
9. 9
   AutreThis material is purified by crystallization from hot (68° C.) ligroin

Mode opératoire

A solution of 2-aminothiophenol (10.7 mL, 0.1 mol) in diethyl oxalate (27.3 mL, 0.2 mol) is heated at reflux for 4 hr. The solution is cooled to rt and poured into a solution consisting of water (150 mL), conc. HCl (50 mL) and 95% EtOH (70 mL). With stirring, the oil dissolved and a solid formed. The solution is cooled in an ice bath, the solid is collected by vacuum filtration and the solids are washed with a solution consisting of EtOH/water (25/75) to afford a dark solid. This material is purified by crystallization from hot (68° C.) ligroin to yield ethyl 2-benzothiazolecarboxylate (7.5 g, 36%): Elemental analysis for C10H9NO2S: Calc: C, 57.95; H, 4.38; N, 6.76. Found: C, 57.99; H, 4.28; N, 6.78.

Source