Carbon Dioxide → HCID 357618, compound

n-Butyl lithium (185 ml, of a 1.42M solution in hexane) was added to a solution of diisopropylamine (37.0 ml), in dry THF (300 ml) at -78° and the the solution was stirred for 0.25 h. A solution of 1,4-benzodioxin-2-carboxylic acid (23.40 g) in dry THF (400 ml) was then added over 0.5 h and the resulting solution was stirred at -78° for 1 h. The solution was then poured onto finely crushed CO2 and the mixture left to stand overnight. The mixture was evaporated and 2N-hydrochloric acid (250 ml) was added cautiously, followed by concentrated hydrochloric acid (40 ml). EA (500 ml) and THF (100 ml) were added to the mixture, which was shaken and the organic layer separated. The aqueous phase was further extracted with EA and the combined extracts were dried. Evaporation of the solvent gave an orange solid which was triturated under ER for 0.5 h. The solid was collected, washed with ER and dried in vacuo to afford the title compound (25.0 g) m.p. 215°-218°.

1. stirringthe resulting solution was stirred at -78° for 1 h
2. waitthe mixture left
3. waitto stand overnight
4. customThe mixture was evaporated
5. addition2N-hydrochloric acid (250 ml) was added cautiously
6. additionEA (500 ml) and THF (100 ml) were added to the mixture, which
7. stirringwas shaken
8. customthe organic layer separated
9. extractionThe aqueous phase was further extracted with EA
10. customthe combined extracts were dried
11. customEvaporation of the solvent
12. customgave an orange solid which
13. customwas triturated under ER for 0.5 h
14. customThe solid was collected
15. washwashed with ER
16. customdried in vacuo

ORD record

ord-817cddf1a49840748243050ac3e436ed

Source dataset

uspto-grants-1985_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04496579