تفاعل #740383

معادلة التفاعل

2,5-dimethoxy-3,4,6-trimethylbenzaldehyde

sodium pyruvate

potassium hydroxide

→

4-(2',5'-dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid

المردود 100.0%

المذيبات

methanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture is subsequently heated
2. 2
   درجة الحرارةat reflux for 5 hours
3. 3
   أخرىwhereby a yellow solution is obtained
4. 4
   أخرىthe resulting 4-(2',5'-dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid is precipitated by the addition of sulphuric acid
5. 5
   workup.STIRRINGThe suspension is stirred for 1 hour
6. 6
   ترشيحfiltered
7. 7
   غسيلthe filter residue is washed with water
8. 8
   أخرىdried

الإجراء التجريبي

A suspension of 3.7 g (17.6 mmol) of 2,5-dimethoxy-3,4,6-trimethylbenzaldehyde and 5.0 g (53.2 mmol) of sodium pyruvate in 20 ml of methanol is treated with 0.1 g (1.8 mmol) of potassium hydroxide and the mixture is subsequently heated at reflux for 5 hours, whereby a yellow solution is obtained. The reaction mixture is poured on to ice-water and the resulting 4-(2',5'-dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid is precipitated by the addition of sulphuric acid while stirring. The suspension is stirred for 1 hour, filtered, the filter residue is washed with water and dried. In this manner there are obtained 4.9 g of 4-(2',5'-dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid in the form of a yellow powder of melting point 126°-127° C.

المصدر