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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1675704Generated: October 31, 2026

Hydrochloric Acid → Hydrochloric Acid

https://huagongshe.com/reaction/1675704

Reaction equation

Participants

RoleNameHCIDCharge
ReactantHydrochloric AcidHCID 313—
ReactantHCID 86619554HCID 86619554—
SolventEthanolHCID 702—
ProductHydrochloric AcidHCID 313—
ProductGefapixantHCID 24764487—

Reaction Steps

A slurry of 5-(2,4-diamino-pyrimidin-5-yloxy)-4-isopropyl-2-methoxy-benzenesulfonamide sulfolane solvate (23.86 kg) in a mixture of ethanol (74.3 kg) and 0.44 N HCl (109.4 kg) was heated to reflux to provide a homogeneous solution of the monohydrochloride salt of 5-(2,4-diamino-pyrimidin-5-yloxy)-4-isopropyl-2-methoxy-benzenesulfonamide. This solution was filtered while hot, then treated with concentrated ammonium hydroxide (3.4 L) to liberate the free base of 5-(2,4-diamino-pyrimidin-5-yloxy)-4-isopropyl-2-methoxy-benzenesulfonamide. The resultant mixture was cooled slowly to 20 degrees C. and the crystalline product isolated by filtration. The filter cake was washed with water (20.1 kg) and dried under reduced pressure at 70 degrees C. to a constant weight of 8.17 kg (57.7% yield based on di-solvate of sulfolane). MP=281-282° C. 1H nmr (DMSO-d6) delta: 1.27 (d, 6H, J=6.9 Hz), 3.41 (septet, 1H, J=6.9 Hz), 3.89 (s, 3H), 5.87 (s (br), 2H), 6.40 (s (br), 2H), 6.98 (s, 1H), 7.01 (s (br), 2H), 7.07 (s, 1H), 7.36 (s, 1H).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08003788B2
Source datasetuspto-grants-2011_08
ORD IDord-25659fdf02974d5094de8c650e014ac8
Source noteuspto-grants-2011_08