Diethyl (ethoxymethylene)malonate → HCID 20438310, compound

HRID 1979747Notes

Reaction equation

HRID 1979747 reaction equation
[CH2:1]([N:8]1[CH:12]=[CH:11][C:10]([NH2:13])=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(O[CH:17]=[C:18]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[C:19]([O:21][CH2:22][CH3:23])=[O:20])C>C(O)C>[CH2:1]([N:8]1[CH:12]=[CH:11][C:10]([NH:13][CH:17]=[C:18]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:24]([O:26][CH2:27][CH3:28])=[O:25])=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 6871Diethyl (ethoxymethylene)malonateHCID 15086161-benzyl-1H-pyrazol-3-amine

Product 1

HCID 20438310HCID 20438310, compound

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

1-benzyl-3-amino-pyrazole, m.p. 57°-59° C. (4 g) was reacted with diethyl ethoxymethylenemalonate (6 g) in anhydrous ethanol (40 ml) at the reflux temperature for 3 hours. After cooling the solution was evaporated in vacuo to dryness. Crystallization obtained by dilution with hexane gave diethyl N-(1-benzyl-pyrazol-3-yl)-aminomethylenemalonate, m.p. 60°-62° C. (7.5 g), which was reacted with polyphosphoric acid (3.2 g: 1.5 g of P2O5 and 1.7 g of H3PO4) and POCl3 (13.5 g) under stirring at 120° C. for 30 minutes. After cooling the reaction mixture was diluted with ice water: neutralization with 35% NaOH gave a precipitate which was filtered and washed with water. Crystallization from methanol gave 6 g of 1-benzyl-7-oxo-1H,7H-pyrazolo[1,5-a]pyrimidine-6-carboxylic acid, ethyl ester, m.p. 172°-173° C., which was hydrolized by heating with a mixture 1:1 of 37% HCl:acetic acid (300 ml) at the reflux temperature for 4 hours. After cooling the reaction mixture was neutralized to pH=6 with 35% NaOH and the precipitate was filtered and washed with water: crystallization from isopropyl alcohol gave 9.7 g of 1-benzyl-7-oxo-1H,7H-pyrazolo[1,5-a]pyrimidine-6-carboxylic acid, m.p. 198°-199° C.

Workup

  1. temperatureAfter cooling the solution
  2. customwas evaporated in vacuo to dryness
  3. customCrystallization
  4. customobtained by dilution with hexane

Sources & evidence

ORD record
ord-c7c9e87a54ac4491872fe5249c43f9cd
Source dataset
uspto-grants-1984_11
Patent number
US04482555

Reaction notes

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