Hydrochloric Acid → HCID 13590072, compound

A solution of 9.3 g. (0.05 mole) methyl 4-bromocrotonate, 3.9 g. (0.05 mole) thiourea and 8.4 g. (0.10 mole) sodium bicarbonate in 200 ml. acetone was heated at reflux for two hours. The resulting mixture was filtered and the filtrate evaporated at reduced pressure to yield 10.0 g. of crude methyl 2-amino-(2-thiazoline)-4-acetate. The methyl ester was dissolved in 60 ml. of 20% (w/w) aqueous methanol, heated with 2.3 g. (0.05 mole) sodium hydroxide and stirred at room temperature for 18 hours. The resulting solution was acidified (pH 1.0) with 6N hydrochloric acid and evaporated to dryness. The solid residue was dissolved in water and washed with methylene chloride. The aqueous layer was separated and evaporated in vacuo to afford a residual oil which solidified upon trituration with acetone to yield 4.5 g (56%). The solid was taken up in methanol, treated with activated carbon, filtered and the filtrate evaporated to give 3.2 g. (40 %) of the title compound, M.P. 177°-179° C. Infrared (KBr) cm-1 : 1610, 1660, 1720, 3100-2600; 1H-NMR (D6 -dimethylsulfoxide) ppm (delta): 2.70 (d, 2H), 3.45 (m, 3H), 3.70 (m, 1H), 4.48 (m, 1H); Mass spectrum (m/e): 159.9 (M+).

1. temperatureat reflux for two hours
2. filtrationThe resulting mixture was filtered
3. customthe filtrate evaporated at reduced pressure
4. customto yield 10.0 g
5. customevaporated to dryness
6. dissolutionThe solid residue was dissolved in water
7. washwashed with methylene chloride
8. customThe aqueous layer was separated
9. customevaporated in vacuo
10. customto afford a residual oil which
11. customto yield 4.5 g (56%)
12. additiontreated with activated carbon
13. filtrationfiltered
14. customthe filtrate evaporated
15. customto give 3.2 g

ORD record

ord-0e7eb94454f44e4db7ffa28d061eb257

Source dataset

uspto-grants-1986_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04582907