Methylaminoacetaldehyde dimethyl acetal

In the autoclave, add 3.00 kg of chloroacetaldehyde dimethyl acetal, 30 kg of 33% methylamine methanol solution, close the autoclave valve, heat up to 130-135 ° C, and the pressure is up to 1.2 MPa, then continue to decrease, and the reaction is incubated for 6 hours. Cool down to 25°C and press into a neutralizer. The temperature was lowered to below 10°C under stirring, 3.26 kg of 40% sodium methoxide methanol solution was added dropwise, and the temperature was kept at 0-5°C for 2-3 hours. After filtration, the filter cake was washed with methanol, and the filtrate was transferred to a distillation pot. Distill methanol at atmospheric pressure until it no longer evaporates, change it to vacuum distillation, turn on brine to condense and collect the intermediate, collect 52-60°C/24mmHg fraction, obtain 2.51kg of methylaminoacetaldehyde dimethyl acetal, GC purity 94.6 %,  yield 83.1%.

Methylaminoacetaldehyde dimethyl acetal can be used as a pharmaceutical synthesis intermediate, such as the preparation of methimazole, the chemical name is 1-methylimidazole-2-thiol, which is an antithyroid drug, and its mechanism of action is to inhibit thyroid endoperoxide Enzymes, thereby hindering the oxidation of iodide absorbed into the thyroid and the coupling of tyrosine, hindering the synthesis of thyroxine (T4) and triiodothyronine (T3). Animal experiments have observed that B lymphocytes synthesize antibodies, reduce the level of thyroid-stimulating antibodies in the blood circulation, and restore the suppressor T cells to normal.

clear colorless to light yellowish liquid

(Methylamino)acetaldehyde dimethyl acetal can be used as a reactant to synthesize:

• Aza[3.3.2] cyclazines by reacting with 5-methyloxazolo[3,2-a]pyridinium salts via synthesis of functionalized 5-aminoindolizines intermediates.
• N-(2,2-Dimethoxyethyl)-N-methyl-3,4-dimethoxyphenylglycine by Petasis reaction with glyoxylic acid and 3,4-dimethoxyphenylboronic acid.
• Substituted imidazoles via copper-catalyzed reaction with various nitriles.

2,2-Dimethoxy-N-methylethanamine is an impurity formed in the synthetic process of Methimazole (M260300), a thiourea antithyroid agent that prevents iodine organification,