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

HRID 2248935Notes

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 (1.38g, 50%): mp. 191°-192° C.: UV λmax (pH 1) 254 nm (ε 5,300), 290 (11,400): UV λmax (pH 7,11) 226 nm (ε 28,900), 300 (14,100). Anal. Calcd. for C5HCl2N3OS: C, 27.04: H, 0.45: C1, 31.93: N, 18.93. Found: C, 26.78: H, 0.61: C1, 32.15: N, 18.66. Single crystal X-ray analysis of 24 showed the structure assignment to be correct.

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-d5d112c6e2824fc2956c28a46826e446
Source dataset: uspto-grants-1991_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05041426

Reaction notes

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