Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea
Reaction equation
[CH:1]1([N:7]=[C:8]=[N:9][CH:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]2)[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[O:16]1CCOCC1>>[C:8]([NH:7][CH:1]1[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1)([NH:9][CH:10]1[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1)=[O:16]Participants
Procedure
0.05 mole of 1,4-dihydroxy-2-naphthoic acid was dissolved in 70 ml of DMF, and 10 ml of a 40% aqueous solution of sodium hydroxide was added dropwise to the solution while introducing nitrogen gas. Then, 0.05 mole of α-bromo-propionylethylamide dissolved in 15 ml of DMF was added dropwise and the reaction was conducted at 50° C. for 3 to 4 hours under agitation. After completion of the reaction, the reaction mixture was poured into ice-hydrochloric acid and crystals were recovered by filtration and recrystallized from acetonitrile to obtain a compound having a melting point of 192° C. Then, 0.01 mole of 1-hydroxy-4-[1-(ethylaminocarbonyl)ethoxy]-2-naphthoic acid so obtained was dissolved in 60 ml of dry dioxane, and 0.01 mole of dicyclohexylcarbodiimide was added to the solution. The reaction was conducted at 50° to 60° C. for 30 minutes under agitation. After completion of the reaction, the reaction mixture was filtered and dicyclohexylurea formed as a by-product was removed. The filtrate was concentrated under reduced pressure and n-hexane was added. Precipitated crystals were recovered by filtration and recrystallized from n-hexane to obtain a compound having a melting point of 95° C. (the yield being 65%). From the results of the elementary analysis, it was confirmed that the compound was the compound (2) illustrated above.
Workup
- customAfter completion of the reaction
- filtrationthe reaction mixture was filtered
Sources & evidence
- ORD record
- ord-e24e3357535548d0ac4373ba5d454e83
- Source dataset
- uspto-grants-1980_06
- Patent number
- US04205990
Reaction notes
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