反应详情

2.8 g. of 5-amino-4-sec.butylamino-6-mercapto-2-methylpyridine-3-carboxylic acid, ethyl ester are refluxed in 10 ml. of formic acid for 12 hours. After this time, the excess acid is removed in vacuo and the residue is dissolved in 10 ml. of water. The aqueous solution is made alkaline with sodium hydroxide and extracted twice, each time with 10 ml. of ether. The ether layer is collected, dried over calcium chloride and evaporated to dryness. The residue, 7-sec.butylamino-5-methylthiazolo[5,4-b]pyridine-6-carboxylic acid, ethyl ester is distilled in vacuo, b. p.0.01 180°-185°, yield 1.8 g. (62%).

1. customAfter this time, the excess acid is removed in vacuo
2. dissolutionthe residue is dissolved in 10 ml
3. extractionextracted twice
4. customThe ether layer is collected
5. dry with materialdried over calcium chloride
6. customevaporated to dryness
7. distillationThe residue, 7-sec.butylamino-5-methylthiazolo[5,4-b]pyridine-6-carboxylic acid, ethyl ester is distilled in vacuo, b
8. customp.0.01 180°-185°, yield 1.8 g