Isobutyl 2-(2-Nitro-Benzylidene)Acetoacetate synthesis

Yield:61312-59-2 63.4%

Reaction Conditions:

with piperidine;formic acid in dichloromethane;water at 27 - 33; for 20 h;

Steps:

1 Experimental part; Example 1: Synthesis of isobutyl 2- (2-nitrobenzylidene) acetoacetate

A reactor was fed with 2-nitrobenzaldehyde (18 kg; 0.119 [KMOL)] and methylene chloride (36 kg). The resultant mixture was heated to [27°-33°C,] added with isobutyl acetoacetate (19.8 kg; 0.125 [KMOL),] and successively, with piperidine (2.62 kg; 0.03 [KMOL)] and 99% formic acid (1.43 kg; 0.03 [KMOL).] The temperature of [27°-33°C] was maintained for a period of 20 hrs. After that time, distilled water (9 kg) was added. The lower organic phase was separated and the aqueous phase was eliminated. The organic phase was concentrated in plenum at an internal temperature of [65°C] max. The reactor was put under vacuum while distillation was continued at an internal temperature of [50°C] max for a period of 1 hr at least, in any case until the mass precipitated. The residue so obtained was treated with 80% acetic acid (36 kg) at 40°-50°C and stirred at said temperature until complete dissolution. The solution obtained was cooled to [25°-30°C] for a period of 1 hr at least, until complete precipitation. The temperature was lowered to [0°-5°C] for at least 2 hrs. Then centrifugation was performed and the precipitate was washed with 80% acetic acid (18 kg) and then with distilled water (54 kg). The solid was dried at [40°-] [50°C] to give 22 kg of dried [ISOBUTYL 2- (2-NITROBENZYLIDENE)] acetoacetate. Yield : 63.4%.

References:

WO2004/2958,2004,A1 Location in patent:Page 3-4