Pyrrolidinyl diaminopyrimidine oxide

Pyrrolidinyl Diaminopyrimidine Oxide is a hair growth stimulant that can be used to treat hair loss. It can also be used in cosmetics to invent a dermocosmetic composition having a whitening or dark circle removal or anti-glare effect by containing a pyrrolidinyl diaminopyrimidine oxide compound as an active ingredient.

Pyrrolidinyl Diaminopyrimidine Oxide is prepared by the reaction of pyrrolidine and 2,6-diamino-4-chloro-pyrimidine N-oxide. The steps are as follows:
Pyrrolidine (7.47 g, 0.105 mol) and 2,6-diamino-4-chloropyrimidine N-oxide (16 g, 0.1 mol) were added to 100 mL ethanol solution, 10% NaOH (0.11 mol) was added dropwise under stirring, and then the reaction was carried out at 80 °C for 120 min. The progress of the reaction was monitored by high performance liquid chromatography. After the reaction is completed, it is cooled to below 5°C, the solvent is removed by filtration, the obtained solid product is washed with water, and recrystallized with hot water to obtain 2,6-diamino-4-pyrrolidinopyrimidine N-oxide as a colorless crystalline solid. Yield 92% (17.96 g), white crystalline powder, mp 276-278°C. IR spectrum (neat), νmax, cm-1: 1195 (C-N), 1346 (C-C), 1463 (N-O), 1613 (C=N), 1651 (C=C), 2856 (C-H), 3265 (C-H), 3298 (O-H), 3428 (N-H). 1H NMR spectrum (500 MHz, DMSO), δ, ppm: 1.87 s (4H, CH2), 3.25 s (4H, N-CH2), 5.08 s (1H, Ar-H), 6.78 s (4H, NH2). 13C NMR spectrum (101 MHz, DMSO), δC, ppm: 26.81, 48.05, 74.81, 153.85, 154.47, 154.60.