Stannous chloride dihydrate → HCID 86740880, compound

HRID 978425Notes

Reaction equation

HRID 978425 reaction equation
[N+:1]([C:4]1[CH:28]=[CH:27][C:7]([CH:8]=[C:9]2[C:13]3[O:14][C:15]4[CH:22]=[CH:21][C:20]([C:23]([O:25][CH3:26])=[O:24])=[CH:19][C:16]=4[C:17](=[O:18])[C:12]=3[CH2:11][CH2:10]2)=[CH:6][CH:5]=1)([O-])=O.O.O.Cl[Sn]Cl>C(O)(=O)C.Cl>[NH2:1][C:4]1[CH:28]=[CH:27][C:7]([CH:8]=[C:9]2[C:13]3[O:14][C:15]4[CH:22]=[CH:21][C:20]([C:23]([O:25][CH3:26])=[O:24])=[CH:19][C:16]=4[C:17](=[O:18])[C:12]=3[CH2:11][CH2:10]2)=[CH:6][CH:5]=1

Participants

5

Reactant 2

HCID 61436Stannous chloride dihydrateHCID 86740881HCID 86740881, compound

Product 1

HCID 86740880HCID 86740880, compoundYield 82.9%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 313Hydrochloric AcidSolvent

Conditions

Temperature
60 °C

Procedure

3-(4-nitro-benzylidene)-1,2,3,9-tetrahydro-9-oxo-cyclopenta[b][1]benzopyran-7-carboxylic acid, methyl ester (3.8 g), was reacted with SnCl2.2H2O (11.5 g) in acetic acid (130 ml) and 37% HCl (26.5 ml) under stirring at 60° C. for 3 hours: after cooling the precipitate was filtered and washed with 2N HCl and water and finely dispersed in 2N NaOH. The precipitate was filtered and washed with water until neutral to give 3-(4-amino-benzylidene)-1,2,3,9-tetrahydro-9-oxo-cyclopenta[b][1]benzopyran-7-carboxylic acid, methyl ester m.p. 265°-268° C. (2.9 g), which was treated with 37% HCl (60 ml) in acetic acid (120 ml) under stirring at 100° C. for 4 hours. After cooling the precipitate was filtered and then suspended under stirring in water containing Na2HPO4 : the precipitate was filtered and washed with water to give 2.1 g of 3-(4-amino-benzylidene)-1,2,3,9 tetrahydro-9-oxo-cyclopenta[b][1]benzopyran-7-carboxylic acid, m.p. 360° C. dec., NMR (DMSO d6) δppm: 2.90 (m) (4H, C-1 and C-2 protons), 3.30 (bs) (2H, NH2), 6.64 (d) (2H, C-3 and C-5 phenyl protons), 7.01 (bs) (1H=CH--), 7.31 (d) (2H, C-2 and C-6 phenyl protons), 7.69 (d) (1H, C-5 proton), 8.19 (dd) (1H, C-6 proton), 8.59 (d) (1H, C-8 proton).

Workup

  1. temperatureafter cooling the precipitate
  2. filtrationwas filtered
  3. washwashed with 2N HCl and water
  4. additionfinely dispersed in 2N NaOH
  5. filtrationThe precipitate was filtered
  6. washwashed with water until neutral

Sources & evidence

ORD record
ord-9a17deee07804c4788b7aa3851cd7630
Source dataset
uspto-grants-1987_05
Patent number
US04665084

Reaction notes

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