Nitric Acid → HCID 13321942, compound

Participants

Reaction Steps

0.325 g of 5H-pyrimido[5,4-b]indole-2-carboxylic acid ethyl ester (Example 3) is stirred in 6 ml of 65% strength nitric acid for 15 minutes at room temperature, then for one hour at 70° C. Thereafter the reaction mixture is poured into ice water and extracted with ethyl acetate. The combined ethyl acetate extracts are evaporated; the evaporation residue is chromatographed on silica gel with a mixture of equal parts of methylene chloride and acetone, thus obtaining 0.012 g of 6-nitro-5H-pyrimido[5,4-b]indole-2-carboxylic acid ethyl ester (mp 318°-325° C.) and 0.023 g of 8-nitro-5H-pyrimido[5,4-b]indole-2-carboxylic acid ethyl ester, mp 304°-306° C.

Provenance & Evidence