1159813-93-0

(3,3-Difluorocyclobutyl)methanamine Hydrochloride (cas# 1159813-93-0) is a useful research chemical. It is the sodium salt of (3,3-Difluorocyclobutyl)methanamine (D235341). It is used in the preparation of benzonaphthyridine acetic acid derivatives as STING modulators useful in treatment and prevention of STING-associated diseases.

A borane-THF solution (1M in THF, 16.20 mmol, 16.20 mL) was slowly added dropwise over 5 min to a solution of 3,3-difluorocyclobutanecarbonitrile (14.70 mmol, 1.72 g) dissolved in THF (5 mL) under nitrogen atmosphere. Subsequently, the reaction mixture was heated to reflux for 20 h. After completion of the reaction, it was cooled in an ice water bath. Methanol (20 mL) was slowly added to quench the reaction. The reaction mixture was concentrated under reduced pressure to give the crude product. The crude product was dissolved in a mixture of methanol (10 mL) and concentrated hydrochloric acid (10 mL) and heated to reflux for 2 hours for acidification. After completion of the reaction, the mixture was again concentrated under reduced pressure. The residue was azeotroped twice with ethanol to remove water and the product was subsequently suspended in ether. The creamy solid obtained was separated by filtration and dried by filtration to give (3,3-difluorocyclobutyl)methylamine hydrochloride as a white solid (1.48 g, 64% yield).

[1] Patent: WO2015/115673, 2015, A1. Location in patent: Page/Page column 89
[2] Patent: EP2738156, 2014, A1. Location in patent: Paragraph 0144-0145