Ethyl Acetate → 5-Methyl-5H-pyrazolo[3,4-d]-1,2,3-thiadiazole-6-carbonitrile

HRID 2291362Notes

Reaction equation

HRID 2291362 reaction equation
[CH3:1][N:2]1[C:9]([C:10]([NH2:12])=O)=[C:8]2[C:4]([N:5]=[N:6][S:7]2)=[N:3]1.S(Cl)(Cl)=O.C(OCC)(=O)C>C1(C)C=CC=CC=1>[C:10]([C:9]1[N:2]([CH3:1])[N:3]=[C:4]2[C:8]=1[S:7][N:6]=[N:5]2)#[N:12]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 24386Thionyl ChlorideHCID 70378428HCID 70378428, compound

Product 1

HCID 703784335-Methyl-5H-pyrazolo[3,4-d]-1,2,3-thiadiazole-6-carbonitrileYield 24.6%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
80 °C

Procedure

The compound, 5-methylpyrazolo-1,2,3-thiadiazole-6-carboxamide (0.9 g, 4.92 mmol) was slurried in toluene (10 mL) and thionyl chloride (0.5 mL) was added. The mixture was heated to 80° C. and then to 105° C. with no reaction. The mixture was cooled to 70° C. and ethyl acetate (10 mL) was added. The slurry was stirred at 70° to 80° C. for 55 h, cooled and concentrated onto Silica Woelm®TSC and chromatographed on 50 g of the same silica (25% ether-hexane) to give after a 300 mL forerun 0.2 g of 6-cyano-5-methylpyrazolo-1,2,3-thiadiazole as a light yellow solid; mp 111° to 114° C.; 1H-NMR (CDCl3) σ 4.41 (s, 3H); IR (KBr) 2230, 1332, 679 cm-1 ; Mass spec. m/e 165.0109; m/e calcd. for C5H3N5S 165.0109.

Workup

  1. customto 105° C. with no reaction
  2. temperatureThe mixture was cooled to 70° C.
  3. temperaturecooled
  4. concentrationconcentrated onto Silica Woelm®TSC
  5. customchromatographed on 50 g of the same silica (25% ether-hexane)

Sources & evidence

ORD record
ord-7c5488cc702b4b09b2aba6d4136bbe2b
Source dataset
uspto-grants-1989_01
Patent number
US04795817

Reaction notes

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