Pyrimidine-5-carboxylate, 1,2,3,6-tetrahydro-1 - -2,6-dioxo

Not all neomycin salts, however, possess advantages such as a reduced toxicity. In fact, the orotic acid(1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidine carboxylic acid) salt was reported to have a greater toxicity than neomycin itself74f75. some uncertainty of this fact is apparent as other authors have reported the two compounds to be of a similar toxicity 6. The salt of neomycin with usnic acid(an antibacterial substance found in lichens) has been reported to have less antibacterial activity than the neomycin used in the preparation of the salt. 

Ring transformation of ethyl 2,4-dioxo-l,2,3,4-tetrahydropyrido[2,3- pyrimidine-5-carboxylates 317 with 80% hydrazine hydrate in boiling ethanol gave a mixture of 5-methyl/allyl/benzylamino-l,2,3,4-tetrahydro-l,4-dioxopyr-ido[3,4-i/ pyridazines 318, pyrido[2,3,4-< <7]pyridazino[3,4-/ [l,2,4]triazepines 319, and a low yield of 2,3,4,6,7-penta-azaphenalene 320. The reaction of 317 with hydrazine hydrate was also performed without a solvent in an oil bath at 125 °C for 1 h to give the same products, but higher yields of 318 and lower yield of 319 as well as traces of 320 were obtained (Equation 25) <1997FA657>. 

Ethyl 2-(Methylsulfanyl)-4,5-dioxo-3,4,5,8-tetrahydro-8-(2,3,5-tri-0-acetyl-/J-D-ribofuranosyl)pyrido 2,3-4]-pyrimidine-6-carboxylate 198... 

Orotic Acid. l,2,3,6.Tetrahydro-2,6-dioxo-4-py-nmidinecartroxyhc acid uracil-6-carboxylic acid whey factor animal galactose factor Oropur Orotyl. CjH.N.O, mol wt 156.10. C 38.47%. H 2.58%, N 17.95%. O 41.00%. A pyrimidine precursor in animal organisms, found in milk Bachstez. Ber. 64, 2683 (1931) Hilbert, J. Am. Chem. Soc. 54, 2082 (1932) Johnson, Schroeder, ibid. 2942. Synthesis from aspartic acid Nye. Mitchell, ibid. 69, 1382 (1947). Prepn by condensation of urea with monoethyl ester of ox -alacetic acid in methanol Scriabine, U.S. pat. 2,937,175... 

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