反应详情

A solution of 2.15 parts of sodium hydrogen carbonate in 40 parts of water was added to a refluxing solution of 3.0 parts of ethyl 4-oxo-7-[7-(2-n-propyl phenoxy)heptyloxy]-4H-1-benzopyran-2-carboxylate in 50 parts of ethanol. More water was added to produce a clear solution which was refluxed for 2 hours. Acidification of the filtrate precipitated the acid as a semi-solid mass which was converted to a fine solid by persistent mechanical disruption of the gum cakes. The solid was filtered off, dried and crystallised from benzene/petrol (bp. 80°-100°) to furnish 2.8 parts of 4-oxo-7-[7-(2-n-propylphenoxy)heptyloxy]-4H-1-benzopyran-2-carboxylic acid as white microcrystals, mp. 149°-150° .

1. customto produce a clear solution which
2. temperaturewas refluxed for 2 hours
3. customAcidification of the filtrate precipitated the acid as a semi-solid mass which
4. filtrationThe solid was filtered off
5. customdried
6. customcrystallised from benzene/petrol (bp. 80°-100°)