Hydrochloric Acid → HCID 18632814, compound

Temperature

0 °C

To solution of potassium (2.15 gm) in t-butanol (45 ml) at room temperature was added dropwise a solution of dimethylsuccinate (14 ml) and 1-naphthaldehyde (7.5 ml). The reaction mixture was then heated to reflux for a period of 30 min. whereupon, it was cooled to 0° C. The reaction mixture was made acidic with HCl (6N, 10 ml) and evaporated in vacuo. The reaction mixture was partitioned between water and diethyl ether and the combined organic fractions were extracted with NH4OH (1N) four times. The combined basic fractions were washed with diethyl ether, and acidified with HCl (3N), and extracted thoroughly with methylene chloride. The combined organic fractions were dried over Na2SO4, filtered and evaporated in vacuo. Without purification the crude methyl-4-carboxy-2-(1-naphthylmethylene)-propionate was dissolved in methanol (100 ml) and to this solution at 0° C. slowly added magnesium turnings (2.3 gm) over a 3 hr period. When all the magnesium had been consummed, the reaction mixture was poured into HCl (carefully, 3N, 150 ml). The reaction mixture was extracted with diethyl ether, dried over Na2SO4, filtered and evaporated in vacuo to give the title compound in its racemic form. This material has been resolved with (+) methylbenzylamine in diethyl ether. Thus 5.2 gm of racemic material has been converted to 2.2 gm of pure R(+) title compound. [α]D =+48.56(EtOAc). NMR (CDCl3) 2.4-2.5(dd,1H), 2.7-2.85(2d,1H), 3.05-3.15(ABq,1H), 3.55-3.7(m,1H), 3.7(S,3h), 7.27(d,1H), 7.3-7.4(t,1H), 7.45-7.6(m,2H), 7.75(d,1H), 7.85(d,1H), 8.05(d,1H).

1. temperatureThe reaction mixture was then heated
2. temperatureto reflux for a period of 30 min. whereupon, it
3. customevaporated in vacuo
4. customThe reaction mixture was partitioned between water and diethyl ether
5. extractionthe combined organic fractions were extracted with NH4OH (1N) four times
6. washThe combined basic fractions were washed with diethyl ether
7. extractionextracted thoroughly with methylene chloride
8. dry with materialThe combined organic fractions were dried over Na2SO4
9. filtrationfiltered
10. customevaporated in vacuo
11. customWithout purification the crude methyl-4-carboxy-2-(1-naphthylmethylene)-propionate
12. dissolutionwas dissolved in methanol (100 ml) and to this solution at 0° C. slowly added magnesium turnings (2.3 gm) over a 3 hr period
13. additionthe reaction mixture was poured into HCl (carefully, 3N, 150 ml)
14. extractionThe reaction mixture was extracted with diethyl ether
15. dry with materialdried over Na2SO4
16. filtrationfiltered
17. customevaporated in vacuo

ORD record

ord-4e58eb56b50b47dc9abb6931e6cce358

Source dataset

uspto-grants-1991_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05039664