تفاعل #950175

معادلة التفاعل

4-oxo-4,5,6,7-tetrahydrobenzo[b]furan-3-carboxylic acid

p-toluenesulfonic acid hydrate

→

desired product

Methyl 4,5,6,7-tetrahydro-4-oxo-3-benzofurancarboxylate

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture heated
2. 2
   درجة الحرارةat reflux for 24 hours
3. 3
   تركيزthe methanol concentrated in vacuo to a residue
4. 4
   workup.DISSOLUTIONThe residue is dissolved in 100 ml of ethyl acetate
5. 5
   غسيلwashed with 30 ml of saturated sodium bicarbonate and 30 ml of brine
6. 6
   تجفيفThe organic layer is dried with Na2SO4
7. 7
   ترشيحfiltered
8. 8
   تركيزthe filtrate concentrated in vacuo to a residue which
9. 9
   أخرىis crystallized from ethyl acetate-hexane

الإجراء التجريبي

To a solution of 2.11 g of 4-oxo-4,5,6,7-tetrahydrobenzo[b]furan-3-carboxylic acid in 100 ml of methanol is added 202 mg of p-toluenesulfonic acid hydrate and the mixture heated at reflux for 24 hours. The reaction mixture is cooled to room temperature and the methanol concentrated in vacuo to a residue. The residue is dissolved in 100 ml of ethyl acetate and washed with 30 ml of saturated sodium bicarbonate and 30 ml of brine. The organic layer is dried with Na2SO4, filtered and the filtrate concentrated in vacuo to a residue which is crystallized from ethyl acetate-hexane to give 1.75 g of the desired product as a white crystalline solid, m.p. 100°-102° C.

المصدر