Hydrochloric Acid → 5,7-Dichlorothiazolo[4,5-d]pyrimidin-2(3H)-one

HRID 1638531Notes

Reaction equation

Cl[C:2]1[S:3][C:4]2[C:9]([Cl:10])=[N:8][C:7]([Cl:11])=[N:6][C:5]=2[N:12]=1.Cl.[OH-:14].[Na+]>>[Cl:11][C:7]1[N:8]=[C:9]([Cl:10])[C:4]2[S:3][C:2](=[O:14])[NH:12][C:5]=2[N:6]=1

Participants

Reactant 3

HCID 313Hydrochloric Acid

HCID 14798Sodium Hydroxide

HCID 145057542,5,7-Trichlorothiazolo[4,5-d]pyrimidine

Product 1

HCID 145057565,7-Dichlorothiazolo[4,5-d]pyrimidin-2(3H)-oneYield 50%

Conditions

Temperature: 60 °C

Procedure

A suspension of the trichloro compound (22: 3.0 g, 12 mmol) in 1N NaOH (35 mL) was heated at 60° C. for 1 h. The solution was treated with decolorizing carbon and then acidified with 10% aqueous HCl. The resulting precipitate was collected and reprecipitated from dilute base with glacial acetic acid to provide 24 as orange needles (1.38 g, 50%): mp. 191°-192° C.: UV λmax (pH 1) 254 nm (ε5,300), 290 (11,400): UV λmax (pH 7, 11) 226 nm (ε28,900), 300 (14,100). Anal. Calcd. for C5HCl2N3OS: C, 27.04: H, 0.45: Cl, 31.93: N, 18.93. Found: C, 26.78: H, 0.61: Cl, 32.15: N, 18.66.

Workup

additionThe solution was treated with decolorizing carbon
customThe resulting precipitate was collected
customreprecipitated
additionfrom dilute base with glacial acetic acid

Sources & evidence

ORD record: ord-844a9065d9874b819ea88307f8bcf131
Source dataset: uspto-grants-1989_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04880784

Reaction notes

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